Software Defined Radio: The Transition from Defense to Commercial Markets (presentation) Kaul, A. (Pioneer Consulting, Woburn, MA)
Software Defined Radio (SDR) until now has been seen as a military technology with a limited market for commercial applications. The commercial use of SDR has been restricted to providing ‘partial software upgradeability’ within a given family of wireless standards. This has been due to technological bottlenecks at the RF front end and its inability to be reconfigurable. However, with recent innovations in enabling wideband RF front ends and soft transceivers, SDR can move beyond ‘partial reconfigurability’ to ‘multiprotocol multiband reconfigurability’. SDR in its new commercial avatar can allow for a smaller hardware footprint leading to lower costs and a shorter time to market. This paper looks at the innovations that are driving this transition and analyzes the critical factors and market dynamics needed to ensure its commercial market success. The paper also provides a realistic discussion around the ability of SDR to initiate disruptive changes in the wireless business model.
An Architecture Framework for Software and Cognitive Radios (presentation) Nicollet, E. (Thales Communications, Paris, France), W. König (Alcatel-Lucent, Stuttgart, Germany), M. Muck, D. Bourse (Motorola Labs, Paris, France)
Development of future Software Defined and Cognitive Radios, and dissemination of current technologies to other industrial domains, are strongly depending on the level of readiness of the associated technologies. The cost-efficiency of such technologies is a determinant driver, which can be improved thanks to standards emergence. An Architecture Framework is proposed in this paper, aiming at capturing intrinsic structuring concepts of the SDR and CR domain, in order to facilitate synergies and, ultimately, facilitate emergence of more affordable solutions thanks to facilitated standards definition. The key concepts introduced by the Framework are the notions of Reconfiguration Modules and Configurable Execution Modules, articulating together so as to cover Reconfiguration Architecture definition needs of any SDR and CR products. The importance of distinguishing Functional and Physical levels of abstraction is identified and underlined. A specific sub-classification is introduced, with a set of formal definitions associated. Consideration on current technological standards and possible perspectives are provided.
FP6 E2R Programme Achievements and Impact (presentation) Dr. Didier Bourse, Dr. Markus Muck, Dr. David Bateman, Dr. Soodesh Buljore (Motorola Labs), Dr. Klaus Moessner (University of Surrey), Mr. Eric Nicollet (Thales Communications), Dr. Enrico Buracchini (Telecom Italia Lab), Pr. Panagiotis Demestichas (University of Piraeus), Makis Stamatelatos, Eleni Patouni, Dr. Nancy Alonistioti (University of Athens)
This paper presents an overview of the different research areas investigated in the Integrated Project End-to-End Reconfigurability (E2R II) project, highlighting the main achievements of the consortium. E2R II is a partly funded project that follows the successful achievements of the first phase and addresses the core of the Strategic Objective "Mobile and Wireless Systems and Platforms Beyond 3G" within the 6th Framework Programme. E2R II is concentrating on most promising solutions identified in E2R I and will assess any emerging new technologies, while in parallel evolving towards an integrated framework. The E2R II project aims to realise the full benefits of the diversity within the radio eco-space, composed of wide range of systems such as cellular, fixed, wireless local area and broadcast.
Session 1.1
An FPGA Framework Supporting Software Programmable Reconfiguration and Rapid Development (paper) Rupe, D. (BittWare, Concord, NH)
The role of FPGAs in Software Defined Radio (SDR) applications has continued to increase in spite of significant development costs. Implementation practices are non-standard as developers work at low abstraction levels, treating FPGAs as a blank canvas. The majority of implementation cycles are spent building and testing external device interfaces and infrastructure to support the end application. The resulting long and drawn out schedules, increased complexity, and overall risk of FPGA inclusion in SDR applications is forcing developers to adopt new implementation practices. This paper introduces an FPGA framework leveraging concepts found in modern software applications. By utilizing software methodologies, this framework not only supports Software Programmable Reconfiguration (SPR) it also makes rapid development of FPGA-based SDR applications possible while decreasing costs and minimizing risk.
A Platform Independent Model and Threat Analysis for Mobile Ad hoc Networks (paper) Martin, A., J. Smith (SCA Technica Inc., NH), M. Koethe (88solutions Corp, MA)
Mobile Ad Hoc Networking (MANET) is a layer on top of an existing wireless network to assist in discovery and multi-hop routing of packets across a network topology. While extensive work has been performed in the field of secure MANET, it has been based on select issues or on incomplete assessment of MANET architecture. Security must be addressed at the base level of a system’s architecture, prior to build, independent of platform, algorithm or implementation. This paper leverages the Platform Independent Model (PIM) for MANET proposed to the Object Management Group (OMG) to serve as the base architecture for addressing the various MANET specific attacks and present a threat analysis of identified assets, vulnerabilities and threats, usable for future deployments, implementations and security work.
Wireless Interoperability for Security - WINTSEC (paper) Blaschke, V., F. Jondral, S. Nagel (Institut für Nachrichtentechnik, Universität Karlsruhe (TH), Germany), E. Nicollet (Thales Communications, Paris, France)
Crises management for homeland security, emergency and peace keeping operations is a communication intensive process that requires the involvement of many agencies and actors. Generally, each organization operates a specific communication system. Unfortunately, in major disaster scenarios these heterogeneous and often incompatible radio communication systems form a serious barrier for efficient and mission-oriented communications. Therefore, there is a strong demand for investigations and developments of enhanced interoperability in public and governmental security (P&GS) systems. Based on the analysis of current solutions, the WINTSEC project envisions future P&GS “seamless” interoperable communication systems implementing a “system of systems” approach that is discussed in this paper.
Partial Reconfiguration Concept in a SCA Approach (paper) Sarlotte, M., D. Maufroid, R. Chau, B. Counil (Thales, Colombes, France), P. Gelineau (Thales, Cholet, France)
Continuous services improvement for Software Defined Radio system leads to use non Corba capable devices such as DSP and FPGA to meet the data rate requirements. The current version of the SCA (Software Communication Architecture) which provides solution for GPP implementation does not covered properly FPGA platform even if latest releases introduces MHAL [1] concept. This paper describes some results achieved in using partial reconfiguration Virtex capabilities. We focus especially on the technologies to manage partial reconfigurability on non Corba enabled devices.
Generalizing Partial Reconfiguration Designs (paper) Neuendorffer, S., C. Epifanio (Xilinx Research Labs, San Jose, CA)
Partially reconfigured FPGA systems are typically architected for a specific design, such as a Software Defined Radio System, with application-specific interfaces and system design. However, we notice that many of the characteristics of such systems are common across a variety of applications. This paper describes a generic system platform, based around a control processor with an operating system and partial reconfiguration that aims to simplify the design of such systems. The platform is implemented using a standard processor design flow targeting the PowerPC 405 processor embedded in Xilinx Virtex 4 FX devices. The design flow used for targeting the user portion of the platform is very similar to the standard (non-partial reconfiguration based) Xilinx design flow. As a result, it is possible to quickly and easily implement a processor-based design using this flow. An example design based on a 2x2 MIMO OFDM system is also shown.
Session 1.2
Methods and Approaches for Abstraction of Hardware Dependencies in Software Radios (paper) Giddings, V. (Objective Interface Systems, Herndon, VA), T. Kacpura (ASRC Aerospace, NASA Glenn Research Center, Cleveland, OH), V. Kovarik (Harris Corporation, Melbourne, FL)
This paper explores abstraction types and levels within the hybrid processor environment of the software radio in the context of NASA deployment of software radio systems. The premise is that abstraction of hardware is more complex than a layer between the drivers and Board Support Package (BSP) for a specific hardware element and the operating system. Due to the power constraints imposed by space flight, many waveforms implementation are driven towards Field Programmable Gate Array (FPGA) and Digital Signal Processor (DSP) implementations. Consequently, hardware abstraction techniques and components must be applied to these processors as well. Furthermore, abstraction approaches must also be integrated with the safety and reliability requirements associated with human space flight. Recent advances in commercially available software will be discussed. The paper will close with a summary of the current landscape and technology areas that require further research.
Modulation Classification for Radio Interoperability via SDR (paper) Bilén, S., A. Price; O. Azarmanesh, J. Urbina (The Pennsylvania State University, University Park, PA)
Robust methods for identifying incoming waveforms, referred to as Modulation Classification (MC), are a capability required for future Cognitive Radio (CR) systems. Most SDR platforms contain an analog front end to receive and/or transmit the signal and a software processor to perform the demodulating and modulating functions of the radio in which the modulation scheme must be known a priori. This research seeks to devise solutions to dynamically identify waveforms by their analog and digital characteristics. The detection would then be used to aid in radio “bridging,” i.e., allowing multiple radio platforms to communicate autonomously with each other. This paper outlines the implementation of an MC system that utilizes a signal’s In-phase and Quadrature (IQ) components to generate a constellation diagram for modulation classification. The goal of the research is to provide a method for classifying the modulation scheme of an unknown signal that is both resource-conservative and robust. We have used a MATLAB and Simulink model- based development environment with SDR hardware from Lyrtech.
Teaching SDR Through a Laboratory-based Course with Modern Measurement and Test Instruments (paper) Arslan, H. (University of South Florida, Tampa, FL)
In this article, a state of the art wireless communication systems laboratory that will provide students with the experience to design, test, and simulate SDR based wireless systems (along with wireless circuits) using modern instrumentation and computer aided design software is introduced. The proposed lab will enhance the current wireless and microwave curriculum significantly, and it will build a bridge between the courses on RF circuits /devices, wireless systems/networks, and digital signal processing (DSP) and DSP/FPGA Labs.
Sending Images Using an SDR Platform (paper) Houle, A., J. Daigneault, J. Déry, J. Fortier, J. Landry, M. Lepage, A. Ouellet-Patenaude (Université de Sherbrooke, Sherbrooke (Qc), Canada), C. Belisle (Communications Research Centre Canada, Ottawa (On), Canada)
We report a mandatory end of degree project, based on SDR technology, undertaken by a team of eight undergraduate Electrical Engineering students at Université de Sherbrooke. Project goals include the development of a SDR unit capable of being reconfigured as commercial AM and FM receivers as well as an FRS transceiver. In addition, the SDR unit must be capable of emulating a digital waveform (FSK) over the FRS band for data transfer, specifically imagery. The prototype is based on a x86 computer for waveform processing, a Universal Software Radio Peripheral (USRP) on which two daughterboards are connected: a custom- made AM/FM RF front-end and a RFX400 daughterboard for the FRS band. Software architecture of the prototype is explained, concentrating on the management of multiple threads running simultaneously. While the project is scheduled to end by December 2007, it is expected that a live demonstration of the prototype will be made at the 2007 SDR Forum Technical Conference.
Low Cost Experimental Software Defined Radio System (paper) Baldwin, G., L. Ruiz, R. Farrell, L. Barrandon (CTVR, IMWS, NUIM Kildare, Ireland)
This paper documents the design of a low cost experimental SDR Platform as a research tool. In order to keep costs to a minimum and provide the maximum flexibility a processor-less architecture is chosen. All signal processing is carried out using a standard notebook computer. The platform consists of four hardware elements. These are baseband transmitter board, baseband receiver board, RF transmitter board and RF receiver board. The baseband transmitter board consists of a USB 2.0 interface and two 16-bit DACs. The baseband receiver board consists of a USB 2.0 interface and two 16-bit ADCs. The transmitter RF board consists of a direct conversion modulator, local oscillator, variable gain RF amplifier and power amplifier. The receiver board consists of a low noise amplifier, a direct conversion down-converter with gain control and a local oscillator.
Session 1.3
Design Tradeoffs in Making a Tunable Transceiver Architecture for Multi-Band (paper) Org, E., R. Cyr, G. Dawe, J. Kilpatrick, T. Counihan (BitWave Semiconductor, Inc., Lowell, MA)
Wireless communications occur in a constantly evolving eco-system of licensed and unlicensed spectrum, complex end-user applications and innovation in terminal and infrastructure design. To satisfy the end-user and provide seamless connectivity, carriers and handset OEMs are developing multi-mode handsets which are capable of supporting diverse services over multiple networks. Though these handsets are increasingly complex, technology advances in material science, process technology and integration have all contributed to a steady improvement in the cost and performance they offer. Advances in process technology generally lead to reduced power consumption and improved performance. Those advances are almost always leveraged to add new features. However the different performance required by each protocol in a multi-protocol multi-band solution, inevitably leads to compromises in cost and/or performance while the combination of technology advances and new features increases design time and complexity.
The Design of Flexible Front End Processing for Ciren (paper) Lee, K., S. Hasan, C. Zhang, C. Dietrich (Wireless @Virginia Tech)
This paper presents the design of a front end for CIREN which uses FRS spectrum as a secondary user. The main goal of the front end is to alleviate an unnecessary burden on a processor and to provide the flexible configuration required by the processor. The design is done on the platform of SFF-SDR. The platform is briefly introduced and a DIF design is discussed in detail. The functions of the DIF are down/up-conversion, decimation, interpolation, and channel sensing. To make a programmable feature for these functions, a DDS and a CIC filter are used. Currently, RX- path in the DIF is completed and TX-path is being designed.
Multi-System Optimization of RF Front End With Relaxation of Requirements (paper) Kitayabu, T., T. Maeyama (KDDI R&D Laboratories, Fujimino, Japan)
In order to offer customers a wide variety of services, mobile handsets have to support many communication standards: CDMA2000, WiFi, and Bluetooth. Multi- mode multi-band transceivers are very much in demand. The terminals have become increasingly complicated as they must support many communication standards. These standards normally require a separate RF front end because each system has different performance requirements. Software defined radio (SDR) technology has attracted attention as a means of realizing multi-system terminals with an associated reduction in terminal size. This paper presents a design concept for a multi- system RF front end for SDR transceivers. Our proposal enables the sharing of RF components with relaxation of the performance requirements, assuming specific application of the SDR transceiver. We present some evaluation results for RF components’ broadband properties and a specific example of multi-system RF front end design.
Test Results of the Direct Conversion Transceiver Demo Board (paper) Panfilov, O., R. Hickling, T. Turgeon, I. Alexandrov, K. McClellan, A. Reamon, L. Linder (Terocelo, Van Nuys, CA)
Direct conversion of received signals into digital form immediately after an antenna allows practically complete elimination of analog elements in the channel. That technology is capable to bring into life a new generation of multi-mode radios that can handle multiple frequency bands, process multiple transmission protocols, be the bases for convergence of different services, able of being reconfigured on the fly, and be easily and cost-effectively upgraded by wirelessly downloading new software releases. Direct conversion technology may be viewed as the practical response to the call for action by many applications such as Dynamic Spectrum allocation, WiMax with its adjustable signal bandwidth as well as many applications based on using multiple systems operating in different frequency bands or even standards (i.e. disaster handling by different first response teams equipped with different radios). The list of applications benefiting from the direct RF signal conversion to its baseband equivalent is invariably growing over time. The paper considers test results of the Direct Conversion Transceiver Demo Board using Lycon™family of transceiver chips and a programmable baseband processor in the WiMax operating environment. Shown results for the measured Error Vector Magnitude values for the 64 QAM signals are translated analytically into more familiar for systems engineers BER values. Operation at different carrier frequencies is reported. Full duplex multimedia communication between BTS-like node and its user counterpart was demonstrated and analyzed.
Session 1.4
Software Defined Radio – Different Architectures for Different Applications (paper) Org, E., R. Cyr, G. Dawe, J. Kilpatrick, T. Counihan (BitWave Semiconductor, Inc., Lowell, MA)
The development of low cost flexible hardware solutions for Software Defined Radio (SDR) to service multi-band multi- protocol devices continues to be a challenging task. Software Defined Radio has the potential to offer the commercial world multi-purpose platforms which can help them profitably deliver low cost and flexible solutions. Reconfigurability will lead to dramatically reduced development cycles and enables faster time to market. To realize those benefits, a multi-mode, multi-protocol SDR consumer device which can support multiple applications must be able to deliver the performance required by each application. Much time has been spent both in literature and development on evaluating and solving the modem portion of SDR architectures. This paper will focus on the benefits of different reconfigurable Radio Frequency (RF) hardware approaches. These approaches are evaluated and contrasted to one another. RF super-sampling, RF sub-sampling, multi-transceiver integration and tunable architectures are compared for a selection of different requirements. Voice, video and data radio protocols are considered in this discussion. Tunable architectures in particular offer designers the ability to better optimize the radio performance since it offers more degrees of freedom to the system engineer who implements a particular application on the radio architecture. Until now tunable RF architectures have proven difficult to implement due to the inherent complexity involved in designing components with multiple operating points on silicon. Recent advances in silicon development and component architectures have enabled the implementation of tunable RF architectures which meet commercial goals for cost, size, performance and time to market.
Miniaturization of Fixed and Tunable Filters - Where and When to Use Integrated Passive (paper) Paulsen, R., M. Spencer (DataSoft Corporation, Scottsdale, AZ)
RF and microwave filters are a major building block in the design of Software Defined Radios (SDR). These filters are used to reduce cosite interference, reduce transmitter spurious emissions, attenuate strong out-of-band signals and reduce transmitter broadband noise. In software defined radios, filters may also be necessary to reduce DAC images and spurs as well as attenuate unwanted received signals that could cause aliasing. As the need to reduce filter size and cost becomes more prevalent, there are several implementation tradeoffs that must be examined. These tradeoffs will lead to the most appropriate design for the intended application based on filter size, cost and performance. The circuit technologies that will be compared in this paper are discrete components, microstrip and Integrated Passive Devices (IPD). This paper will present an overview of Integrated Passive Device technology and present examples of fixed and tunable filters that range in frequencies from 30 MHz to 6 GHz. These filters have achieved size reductions of approximately 80%. We will also describe design and performance tradeoffs for IPD filters implemented on different types of substrate materials.
Optimization of Wireless Communications Applications Using Differential Evolution (paper) Storn, R. (ROHDE & SCHWARZ GmbH & Co. KG Radiocommunications Systems Division)
Differential Evolution (DE) is a very simple yet powerful algorithm for finding the global minimum of multivariate functions. Since DE belongs to the so-called direct search methods it can also handle functions which are hihgly nonlinear, non-differentiable, mixed-integer or even discrete. Also constraints can be incorporated with relative ease. This broad applicability makes DE a suitable candidate for design taks in wireless communications that are difficult to tackle otherwise. Real-world examples are RF-circuit design, filter design, antenna optimization, construction of error correcting codes for CDMA and others. This contribution shows possibilites how to transform a design task into a minimization task, which then can be solved with a global optimization method like DE. It introduces the most effective variants of DE and, as an example, details a digital filter design problem which was successfully used for a channel simulator at Rohde & Schwarz.
Multiband Multistandard Delta-Sigma-Based RF Transmitters (paper) Hatami, S., R. Negra, F. Ghannouchi, M. Helaoui (iRadio Lab, ECE Department, University of Calgary)
This paper proposes a new approach for implementing RF Delta-Sigma (DS)-based transmitters by considerably reducing the speed requirements of the digital processing block. The novelty relies in using a specific wave modulation in combination with a lowpass DS modulator to produce high frequency digital-like signals which can be used to drive highly-efficient switching-mode PAs. This allows obtaining reconfigurable all-digital multistandard and multiband wireless transmitters with increased flexibility, efficiency and linearity.
The Application of a Novel Adaptive Dynamic Voltage Scaling Scheme to Software Defined Radio (paper) Dolwin, C. (Toshiba Research Europe Ltd, Bristol, UK)
This paper presents a novel technique for using Adaptive Dynamic Voltage Scaling (A-DVS) in Software Defined Radio (SDR). It is well known that high power consumption is a major stumbling block to the introduction of SDR into the commercial handset market even so it is highly desirable to use a generic System on Chip (SoC) in a wireless platform so that it can be reconfigured either when the handset is manufactured or at run-time. This approach addresses the ever demanding issues of increased Radio Access Technology (RAT) complexity and the associated high engineering costs. By using A-DVS in a generic SoC, you are able to dynamically and automatically optimise the resources to match each new configuration and therefore reduce the power consumption.
Session 1.5
An Elemental Computing Architecture for SD Radio (paper) Kelem, S., B. Box, S. Wasson, R. Plunkett, J. Hassoun, C. Phillips (Element CXI, Milpitas, CA)
This paper described a new reconfigurable architecture that lends itself to parallelizable tasks, such as Software-Defined Radio, while providing a new level of reliability for systems built with this architecture. A new computing paradigm called Elemental Computing efficiently combines four computational styles: sequential, data-flow, message- passing, and DMA in a rapidly-reconfigurable distributed system on a chip. We call this an Elemental Computing Array (ECA). Elemental code can be placed and routed in real time to work around defects on a device. This extends the useful lifetime of applications using this device, allowing graceful degradation of the system instead of catastrophic failure.
Designing a Reconfigurable Processing Datapath for SDR over Heterogeneous Reconfigurable (paper) Delahaye, J. (DGA/CELAR, French MoD, Bruz, France), P. Leray, C. Moy, L. Godard, A. Nafkha (IETR/Supelec-SCEE Laboratory, Campus of Rennes, France)
The implementation of a dataflow application on a heterogeneous platform has to tackle with several design issues and should take into account many design trade-offs. One of the design issues is the connectivity between processing functionalities due to the variety of communication interfaces in a heterogeneous system. To overcome this issue system designers have often to choose suitable abstraction level software mechanisms to ensure communication between different DSPs/FPGAs, thus introducing some protocol overhead decreasing the application performance. On the contrary, the implementation of the processing datapath architecture we propose here is at a low level of abstraction and offers a lightweight approach for designing flexible baseband applications. It particularly suits to heterogeneous designs involving FPGAs being dynamically reconfigured in the context of Software Defined Radio - SDR - systems.
Putting Switched Fabric Technology to Work for Software Radio (paper) Hosking, R. (Pentek, Inc., Upper Saddle River, NJ)
The most difficult problem for designers of high- performance, software radio systems is simply moving data within the system because of data throughput limitations. Driving this dilemma are processors with higher clock rates and wider buses, data converter products with higher sampling rates, more complex digital communication standards with increased bandwidths, disk storage devices with faster I/O rates, FPGAs and DSPs offering incredible computational rates, and system connections and network links operating at higher speeds. Traditional system architectures relying on buses and parallel connections between system boards and mezzanines fall far short of delivering the required peak rates, and suffer even worse if they must be shared and arbitrated. New strategies for solving these problems exploit gigabit serial links and switched fabric standards to create significantly more powerful architectures ideally suited for embedded software radio systems.
The Sandblaster SBX 2.0 Architecture (paper) Glossner, J., M. Moudgill, D. Iancu, G. Nacer, S. Jinturkar (Sandbridge Technologies, Inc.), M. Schulte (Sandbridge Technologies, Inc. and University of Wisconsin, Dept. of ECE)
Sandbridge Technologies has developed a new architecture that supports wireless data rates necessary for 3.5G and 4G systems. Building upon the Sandblaster 1.0 architecture, the fully object code compatible Sandblaster SBX 2.0 architecture extends support for high bit-rate processing, MIMO-OFDM acceleration, wider vector execution, and code compression. Architectural performance improvements range from 4x to more than 10x for a variety of signal processing applications while providing 100% object code compatibility with the Sandblaster 1.0 architecture. In this paper we describe the base Sandblaster 1.0 architecture and introduce the Sandblaster 2.0 enhancements.
Session 1.6
All Digital FPGA-Based FM Radio Receiver (paper) Zhang, C., C. Anderson, P. Athanas (The Bradley Department of Electrical and Computer Engineering, Virginia Tech)
This paper presents the design and implementation of the field-programmable gate array (FPGA) based all-digital frequency modulation (FM) radio receiver with a general- purpose RF front-end. The objective of this paper is to build a FPGA based, fully digitized FM radio receiver including a digital tuning function. This receiver consists of a simple analog RF front-end, an Analog-to-Digital converter (ADC), a FPGA chip and a Digital-to-Analog Converter (DAC). The Virginia Tech software defined UWB board is used as the hardware platform of the radio receiver in this project. This board is built by Dr. Chris Anderson, and equips with an 8-bit 1GSPS ADC and a Virtex2pro70 FPGA. A DAC evaluation board and a radio scanner are used to output the audio. A personal computer (PC) plays the role of the controller to tune the receiving frequency through the RS-232 port.
A Phase-Locked Loop with Arbitrarily Wide Lock Range for Software-Based Radios (paper) Akoum, S., B. Farhang-Bouroujeny (University of Utah, Salt Lake City)
Phase locked loops (PLLs) are frequently used in Software Defined Radios (SDR) for carrier recovery and symbol timing synchronization. Unfortunately, conventional PLLs can function correctly only when the frequency offset remains within a relatively small and limited range. This limited lock range is a direct consequence of the inability of the phase detector to resolve any phase error that lies outside a given 2π range. In this paper, we propose an extended lock range PLL that benefits from the flexibilities offered when the design is implemented in software. We describe and examine the FPGA implementation of a tracking system that uses the extended range PLL to perform carrier recovery. The proposed system is applicable to both QAM and PSK signaling and shown to function at a relatively fast clock frequency using a very small percentage of the resources on a Xilinx Virtex-IV FPGA.
Performance Analysis of Digital FPGA-Based Zigbee Receiver on Harris Software Defined (paper) Meng, T., C. Zhang, P. Athanas (The Bradley Department of Electrical and Computer Engineering, Virginia Tech)
A software defined ZigBee receiver has been designed, implemented and tested with a commercially available off- the-shelf ZigBee transceiver. This system is based on the software defined system-in-package (SIP) platform by Harris Corporation (Melbourne, Florida, USA). This platform is equipped with a high-resolution analog-to-digital converter (ADC) and four Xilinx Virtex-4 FPGAs. An all- digital phase-locked loop (PLL) and ZigBee demodulator have been created to operate inside the FPGAs. The ZigBee medium access control layer is also implemented inside an FPGA to allow the system to recover the commercial ZigBee signals. A simple RF front-end is composed of commercially available off-the-shelf components chosen for this system. This work permits a large portion of the RF and IF hardware chain, as well as the physical layer and medium access control layer, to be reconfigured inside the FPGAs. A streaming video source emanating from the XBee ZigBee transceiver is demonstrated on the SIP in real time.
Common Operators Design on Dynamically Reconfigurable Hardware for SDR Systems (paper) Godard, L., H. Wang, C. Moy, P. Leray (IETR/Supelec-SCEE Laboratory, Campus of Rennes)
This paper deals with common operators used to perform multi-standard, multi-function applications. In opposition with highly complex communication components, each exclusively dedicated to a given standard ("Velcro" approach), we argue that one of the key point in software radio is the (re)use of modular operators as proposed in [1]. Those operators can adapt their behavior according to the function to realize by parameters change. This indicates the need to dynamically adapt systems architecture at the hardware level. Taking into account the possibility of partial reconfiguration offered by the FPGA [2], we can reconfigure common operators while the rest of the design is still running. Common operators approach also offers possibility to use reconfiguration by difference that aims at reducing bitstream size and then decrease the cost of the reconfiguration in terms of memory and time allocation.
Leveraging SystemC And OCP to Improve the Verification of FPGA-Based Software Defined Radio (paper) Noseworthy, J. (Mercury Computer Systems, Inc., Chelmsford, MA)
The design complexity of the modern day Software Defined Radio (SDR) is increasing as system designers continue to explore ways to successfully integrate Field Programmable Gate Arrays (FPGAs) into SDR-based systems. One of the many challenges associated with the integration of FPGAs into SDR-based systems is verification at both the component and system levels. Unlike software-based components which can rely on common interface standards such as those set forth by the Software Communication Architecture (SCA), FPGA- based components have no common standard upon which to draw. This makes it extremely difficult to leverage verification Intellectual Property (IP) assets across multiple FPGA-based components since each component could potentially have a unique interface. The result is a time-consuming process of customizing verification IP to suite the needs of a particular FPGA component interface. Another challenge of introducing FPGAs into SDR- based systems is verification at the system or application level. Typical systems are heterogeneous, containing a mix of FPGAs and other devices operating at varying levels of abstraction. This degree of heterogeneity makes the provision of a single verification environment, in which both hardware and software elements can be verified, difficult.
Session 2.1
Universal Synchronization Design for Cognitive Radio (paper) Wang, Y., Q. Chen, B. Le, C. Bostian (Wireless @ Virginia Tech, Virginia Tech)
Synchronization technology is one of the key design issues of wireless communication systems. Unlike conventional standard-specific radios, in cognitive radio (CR) applications where multiple modulations can be used to achieve waveform agility, the CR needs to extract the key features from the received signal to accomplish classification, synchronization and demodulation, all without any prior knowledge. This paper presents a universal signal synchronization design that supports a variety of modulations, including: digital PSK, FSK, QAM and analog AM and FM. In a CR receiver, carrier synchronization largely relies on modulation classification. Before a phase lock loop, the complex envelope based features can be extracted from the quasi-baseband signal to classify FM, AM, BFSK, BPSK. Then, based on a keying rate detection, the incoming signal can be categorized into a modulation group, i.e. real or quadrature, linear or non-linear, analog or digital, amplitude-, frequency- or phase-modulated, even if its exact modulation order has not been identified. Our universal synchronizer adjusts its loop gain, loop bandwidth, and number of branches to adapt to the target modulation group. Considering CR’s requirement for flexibility and reconfigurability, we chose an I/Q synchronization structure. It can act as a Costas phase-error feedback loop for digital modulations and also be configured as generic real phase lock loop (PLL) for FM. For digital modulations, the in- phase and quadrature baseband information can be obtained and then used to classify and demodulate high-order modulations. In this paper, the universal synchronizer is simulated and verified in Matlab and then implemented in our software defined radio platform, which is developed using GNU Radio and USRP. Carrier synchronization reconfiguration and adaptation are achieved in real time through a purely software defined implementation approach.
SDR Analog Front-End Architecture For Simultaneous Digitalization of Data Transmission (paper) Cattoni, A., M. Musso, C. Regazzoni (Department of Biophysical and Electronic Engineering (DIBE), University of Genova)
In the last years, an increasing interest of the market in devices able to integrate navigation and communi- cation technologies has been noticed. Software Defined Radio technology helps in a tight integration of all possible radio signals into one, completely reconfigurable, universal device. In this work the problem of the parallel acquisition and demodulation of Galileo, Satellite UMTS (S-UMTS) and IEEE 802.11b local wireless LAN has been faced through the usage of a multi-stage super-heterodyne analog front-end able to overlap the different signals into a reduced bandwidth. In this way it is possible the usage of low-cost components both for the analog heterodyne front and for the A/D Converter.
Capacity Growth of a CDMA2000 Base Station Due to Moores Law (paper) Chapin, J., A. Chiu, V. Lum, J. Nimmer (Vanu, Inc., Cambridge, MA)
The software radio technology used by Vanu, Inc. is designed to deliver ongoing performance improvements to customers. An all-software approach, eliminating low-level firmware such as VHDL for FPGAs or DSP assembly code, enables low-cost porting of waveforms to new processors and platforms as they become available. This enables exploiting the Moore’s Law growth curve of the semiconductor industry. This paper evaluates the success of this approach by reporting performance improvements delivered for a particular waveform, CDMA2000 1xRTT, across multiple hardware generations.
Session 2.2
Validation and Verification of Modular Software for Software-Defined Radios (paper) Aguayo Gonzalez, C., J. Reed (Wireless@Virginia Tech, Virginia Tech)
The future of wireless technology relies on the flexibility provided by Software-Defined Radio (SDR). This technology enables the development of exciting new applications and promises drastic reductions in development costs. However, there are many challenges that must be overcome before the full potential of SDR can be reached. In particular, the appropriate validation and verification techniques are needed to ensure the quality of SDR systems and their software components. This paper presents a framework for the validation and verification of modular software for SDR. It includes development and management techniques, tools, and metrics that facilitate quality assurance in SDR modules and systems. This approach enables agile development techniques, facilitating unit and integration testing strategies. We describe the features that make modular and SDR software testing unique and suggest techniques to address them, along with the tools and infrastructure required. Elements of this framework are applied to the SCA-based CIREN system being developed at Virginia Tech as part of the Smart Radio Challenge. The general principles, however, are applicable to any component-based architecture.
Performance Analysis of Array Antenna System Using Multiuser Detection and HARQ (paper) Oh, T., N. Ryu, S. Choi (HY-SDR Research Center, Hanyang Univ., Seoul, Korea), W. Lee (Dept. of Information and Communications, Yong-In Songdam College, Yong-In, Korea)
Multi-user detection(MUD) technique eliminates both inter-symbol interference (ISI) and multiple-access interference (MAI) in the received signal over time-varying multipath channels. Hybrid ARQ(Automatic Repeat reQuest)(HARQ) technique combines the advantages of FEC and ARQ and offers much better performance, especially for time-varying multipath channels. In this paper, we analyze a smart antenna system and diversity antenna system using MUD and HARQ. In general, the smart antenna system can increase the capacity of a mobile radio network due to the capability of mitigating the interference. The diversity antenna system can improve the reliability of a received signal by utilizing two or more communication channels with different characteristic, in order to combat fading and interference. By using the HARQ technique, the smart antenna system and diversity antenna system improved a performance due to increase diversity order. The performance analysis of smart antenna system and diversity antenna system is shown in terms of BER (bit error rate) and complexity in the HSDPA (High-Speed Downlink Packet Access).
The Myths of Code Portability (paper) Epifanio, C., M. Uhm (Xilinx, San Jose, CA)
Code portability, or, more generally, code reuse, is a long-standing technique to reduce system development costs. It forms a key tenet of JTRS and other transformational defense programs. However, a number of ancillary assumptions must be met in order to reap significant cost reduction. Improper reuse may actually have the undesired effect of increasing development costs. In this paper we explore the myths and realities of code portability. We discuss the assumptions that must be true in order for reuse to succeed, and contrast that with the realities that we observe in the field. Many problems derive from the fact that the developer and reuser may reside in different, often competitive organizations. While the burdens of designing for reuse are borne by the developer, the benefits accrue to the reuser. The focus will be on FPGA code, as both the difficulty and the need for portability are arguably greater than for GPP/DSP code, though the general concepts presented are applicable to all.
An Iterative Maximal Ratio Combiner for Use with Turbo Encoded Waveforms Over a SIMO Rayle (paper) Sawyer, B., J. Reinking (Welkin Sciences, LLC, Colorado Springs, CO), A. Corder, T. Ooi (Missile Defense Agency, Huntsville, AL)
A method is proposed for coherently demodulating and decoding turbo-coded binary phase-shift keyed (BPSK) burst transmissions over a SIMO (single-in, multiple-out) channel. Each individual channel of the overall SIMO channel experiences mutually independent and identically distributed fading. The proposed receiver linearly combines outputs from multiple antennae using a maximal ratio combiner (MRC) with combiner weights determined using a channel estimator. The channel estimator utilizes both pilot symbols and bit decisions from the turbo-decoder to generate the MRC weights. The initial turbo-decoder iteration of the channel estimator uses only pilot symbols. On subsequent turbo-decoder iterations, bit decisions from the turbo-decoder are used for a decision-aided refinement of the channel estimate using all channel symbols. Performance is evaluated using simulation techniques and compared to performance of two variations of the proposed MRC receiver, one using a clairvoyant channel estimator, the other using only pilot symbols for channel estimation.
Latency Profiling for Software Radio: A Case Study (paper) Tsou, T., P. Balister, J. Reed (Wireless@Virginia Tech, Blacksburg, VA)
Timing and latency are critical design parameters in the development of a communication system. With software radio and packet based methods emerging as viable replacements for traditional static solutions, different approaches are necessary to analyze the timing characteristics of these communication environments. This paper presents important concepts for performing timing and latency profiling within the OSSIE SCA software radio framework operating on the Linux operating system. Furthermore, relevant factors and parameters pertaining to latency performance are measured and compared. Specifically, the operations of inter-component communication within a collocated environment are explored.
Session 2.3
Multi-Rate Synchronization of Digital Receivers in Software-Defined Radios (paper) Gaeddert, J., H. Volos, D. Cormier, J. Reed (Wireless@Virginia Tech, Virginia Tech)
This paper describes a multi-rate synchronizer that makes use of a polyphase filter bank to simultaneously perform matched-filtering and interpolation to correct for symbol timing offsets observable on a sampled-data receiver. Interpolation between available sample points is achieved by selecting the appropriate filter in the bank which provides the optimal sampling time. Furthermore, carrier phase error is corrected by adding a second control loop to drive a numerically-controlled oscillator before matched filtering, mitigating distortion caused by any carrier offset. This design is tractable for burst-mode transmissions where symbol timing and carrier frequency/phase acquisition is nec- essary for each data frame and allows for symbol timing and carrier offset estimators to be used in conjunction with the loop control architecture provided. Simulations under various timing and carrier impairments are provided.
FFT Pruning for Complexity Reduction in OFDM Based Combined Cellular and Short Range Network (paper not available) Kristensen, J., F. Fitzek (Aalborg University, Department of Electronic Systems, Aalborg, Denmark)
This paper advocates the use low complexity methods for computing the FFT in the receiver of a mobile device participating in a cooperative scenario. Specifically we consider FFT pruning to reduce the processing complexity in the processing of sub-carriers in an OFDM based cooperative scenario. Our results indicate a reduction in FFT processing complexity, but the results depend on the choice of architecture. Our performance metric is number of arithmetic operations and the requirement is flexibility and efficiency.
A High Speed Wireless LAN Radio Receiver in Software (paper) Ismail, M. (Toshiba Research Europe Ltd., Bristol, UK)
As wireless LAN speeds increase on the back of ever more sophisticated processing algorithms the commensurate need for greater processing power becomes a challenge. The mass-market computing world has recently seen a move away from ever increasing clock speeds to multi-core platforms. Thus, with potentially redundant computing power the question of applying it to realise the core functions of a high-speed wireless LAN was investigated. Three functions central to any future high-speed wireless LAN demanding significant computational resources were identified, Fast Fourier Transform (FFT), matrix decomposition and channel decoding (error correction decoding). These functions were implemented on a standard server platform with an Intel Xeon™ processor with execution times benchmarked for different solutions.
Cyclic Equalization Options in Software-Based Radios (paper) Farhang-Boroujeny, B. (University of Utah: Salt Lake City, Utah)
We discuss application of linear equalizers to multipath wireless channels. We also note that the class of linear equalizers is divided into two subclasses: symbol-spaced and fractionally-spaced equalizers. We present a review of these two subclasses and contrast them against each other by presenting examples of radio channels. This study reveals that with a 20 to 30% increase in computational complexity, fractionally-spaced equalizers perform significantly better than their symbol-spaced counterparts. We emphasize on packet data transmission and introduce the cyclic equalizers for initialization of equalizer. We review the past literature of cyclic equalizers and present a novel implementation with a number of performance advantages over the methods of the past literature.
An Improved Architecture for Implementing Narrow Bandwidth Low Pass Recursive Filters (paper) harris, f. (San Diego State University)
The poles of a recursive digital filter shift their position when the denominator polynomial coefficients are quantized to a fixed bit width approximation. The size of the root migration due to coefficient quantization increases with filter order and is more severe with reduced bandwidth. A sufficient number of bits must be allocated to the quantized coefficients to pre- serve the spectral fidelity of the filter design. Narrowband low pass filters also exhibit large numerical gain which leads to extended bit width requirements for internal registers and multipliers. We present a technique to implement high order very low-bandwidth recursive lowpass filters without the brute force requirement for extended precision coefficients and registers.
Session 2.4
Software Defined Radio Solutions Commercial Solution Takes JTRS to the Battlefield (paper) Turner, M. (Harris Corporation, Rochester, New York)
The Joint Tactical Radio System (JTRS) Program continues to be a key U.S. Defense Department-wide transformational program with the purpose of supporting the U.S. DoD objective for information superiority on the battlefield. JTRS is a driving force behind the advancement of military Software Defined Radio (SDR) solutions and associated technology to meet the growing demand of war-fighters’ communications needs, including: voice, data and video. The JTRS Software Communications Architecture (SCA) [1] continues to mature through specification evolution, the testing and certification of multiple implementations and recently with the release of a set of Application Programming Interface (API) definitions. This paper discusses the changing objectives of the JTRS Program to an “Enterprise Business Model” with the intention to maximize competition and increase industry accountability. A commercial development approach to JTRS that meets these challenging objectives will be described, which includes the deployment of thousands of Harris Hand-held radios with the only JTRS Information Repository waveforms and Cryptographic Equipment Applications (CEAs) operating in the Battlefield today. The Harris AN/PRC-152 Hand-held radio is National Security Agency (NSA) Type 1 certified [1] and “certified SCA compliant” without waivers by the JTRS JPEO [2]. Harris has developed an SCA based Project 25 Waveform for the AN/PRC-152 (C) Hand-held radio to support interoperability between the military and various first responders in support of multi-organization responses to such events as Hurricane disaster relief.
Performance Assessment of Software Interfaces for the Software Communications Architecture (paper) Gudaitis, M., C. Nelson (L-3 Communications, Rome, NY)
This paper discusses results of performance measurements of the Software Communications Architecture (SCA) and the Packet Application Program Interface (API). A test application is developed to assess the performance of interprocess communication in an SCA v2.2.2 compliant environment. The operating environment is based on the OrcaCF using three different Object Request Brokers (ORBs), TAO, OmniORB, and ORBexpress, to measure the effect the ORB has on timing and latency of data flow using the Packet API. The target environment is x86 computers running Linux in a dual node configuration interconnected through an Ethernet switch. Various packet sizes are used in order to assess the effect that packet size has on efficient data exchange. The hypothesis is that the lower bound on the data transfer time is constrained and dominated by TCP, which is the default protocol used by ORBs to communicate among distributed objects. Therefore, a non-SCA non- CORBA application is included in the performance measurement to quantify the lower bound of transport time using TCP as the transport protocol between distributed software components.
Software Engine Development for SDR (paper not available) Sánchez Mora, M., I. Ruiz, G. Baldwin, R. Farrell (CTVR, IMWS, NUI Maynooth, Kildare, Ireland)
This paper focuses on the development of the software engine for an SDR hardware platform [1][2]. This SDR hardware system operates across the frequency band from 1.6GHz to 2.5GHz with the capability to support the GSM1800, PCS 1900, UMTS-FDD, UMTS-TDD and 802.11b standards. It consists of TX/RX RF front-ends, data converters and the USB 2.0 PHY interface.
Interconnecting JTRS SCA Applications (paper) Lévesque, F., S. Bernier (Communications Research Centre, Ottawa, ON)
The Software Communication Architecture (SCA) provides a way of developing reusable applications. An SCA application implements a communications standard though the use of software components which implement signal processing functionality. The software components are reusable and can be interconnected through ports. The SCA however falls short on specifying how applications can be interconnected to create super-applications. Such applications can provide aggregated services such as cross-banding and bridging. The SCA currently specifies that applications can have external ports but does not cover how to interconnect applications. Radio developers have thus been using different proprietary techniques to connect applications. This paper presents a simple way of interconnecting applications. The proposal is an extension to the SCA specification and has been designed to limit the changes to the behavior of the Core Framework only. The proposal does not require any new XML profile which is great for backward compatibility with existing tools and Core Frameworks.
Memory Usage of a Software Communication Architecture Waveform (paper) Balister, P., C. Dietrich, J. Reed (Wireless@VT, Virginia Tech)
One question commonly asked about software definedradiosis “How much memory do I need?”. While the answer depends greatly on the software framework and underlying operating system, this paper describes tools used to measure memory usage on a Linux based system running the OSSIE SCA framework. In addition to the conventional tools commonly used to study memory usage, this paper introduces the exmap and exmap-console tools for performing detailed memory usage measurements. Results from these measurements help define how much memory a radio requires by accurately measuring memory usage. Accurate memory usage measurements allow the system designer to reduce the number of memory chips in the final hardware design, this leads to lower cost radios that require less power to operate.
Session 2.5
Turbo Product Code Implementation on AltiVec Extension to PowerPC (paper) Agarwal, S., J. Singh, M. Rahaman (DEAL, Dehradun, Uttarakhand, India)
Real time implementation of coding schemes suitable for radio application with high throughput requirement in low SNR conditions poses a serious challenge to the overall radio design. Amongst various channel coding schemes, Turbo-Code is the most promising choice in many radio systems forhigh data rate services with superior BER performance. However, turbo decoding is highly computationally intensive, and its real time implementation requires considerable processing power. To address this issue, we propose a new Vectorized approach for implementing Turbo Product Code (TPC) Decoder on PowerPC based COTS hardware used for developing SDR based communication systems. In this paper, we have discussed the implementation and performance of Scalar as well as Vectorized version of TPC decoder based on extended block code BCH (16,11,4) on G4 generation of PowerPC MPC7447A. Both the versions of TPC decoder when compiled using the WindRiver diab Compiler (version 5.4.0) with the same compiling, linking and optimization options, the Vectorized approach offers both significant speedup and complexity reduction over the conventional Scalar implementation.
A DSP Micro-Framework (DSP µF) for OMG SWRadio Specification Extension (paper) Lafaye, F., E. Nicollet (Thales Communications)
The paper begin with the impact of Software Defined Radio on DSP Operating Environment with a focus on the technical services. It aims at describing the specification of the DSP µF. A focus is made on the dynamic loading and the connection process. It will also describe its implementation in the Flexible Base Station Demonstration works made during the E2R European project. The paper then gives metrics concerning the footprint of the solution in comparison with others related solutions.
Session 2.6
Commercial Wireless Metalanguage Scenario (paper) Cummings, M. (enVia Technology Partners, Atherton CA), P. Subrahmanyam (Stanford University, Palo Alto, CA), T. Cooklev (San Francisco State University, San Francisco, CA), B. Lyles (Telcordia Technologies, Piscataway NJ)
In this paper we analyze the current state of multimode cognitive devices and networks, heterogeneous handoff protocols, and trend towards “open access”. It is noted that these powerful trends increasingly require a standard mechanism that enables ecosystem participants to communicate in non-traditional ways. Furthermore, we present commercial scenarios that further motivate such a standard. The rationale for an Industry Standard Metalanguage along was recently presented in [1, 9]. The goal of such a metalanguage is to enable a mechanism that provides a standard communication interface to each of the value chain participants on one side and to the radio systems (hardware and software) on the other side. The metalanguage description can contain information about hardware / software functionality / configuration, Air Interface Standards, the information being exchanged, and end users. We discuss characteristics of the metalanguage for standardizing mechanisms for real-time communication of configuration information across a network that supports both legacy and configurable components. These mechanisms allow an element in such a network to determine the range of capabilities of a configurable node, and/or to request specific functionality.
Architecting Software Radio (paper) Berg, H., A. Ahtianen, A. Parssinen, J. Westmeijer, U. Lucking (Nokia Research Center, Helsinki, Finland)
Applying design principles and methodologies constituted in the software domain and being adapted to the complete execution environment provides new perspectives for future multi-radio computers. The overall system architecture will allow hardware/software repartitioning and different hardware variants depending on prior defined requirements without extensive software rewrites. This demanding target can be addressed from two directions. Firstly, as implementation technology advances it has to be possible to move services, or functionality, previously implemented in hardware to software or vice versa. Secondly, due to cost, power consumption, time-to-market or other customer needs the architecture has to support the creation of also hardware variants which still conform to the prior agreed system specification. This paper will present the utilized concepts and corresponding benefits to constitute the proposed architecture and platform for future radio computers.
Verification Procedure for Reconfigurable Terminal Configurations (paper) Gultchev, S., K. Moessner (Mobile Communications Research, Centre for Communication Systems Research, University of Surrey Guildford)
SDR technology is becoming integral to link different wireless technologies, and to enable interoperability between them. This raises the question of the need for SDR related standards and suitable regulation allowing the use and deployment of SDR technology. Standard compliance and a system’s correct functioning are generally the most critical problems and they need to be ensured. Addressing conformity and correct functionality, software and configuration verification and validation techniques are needed. These important requirements have to be agreed and satisfied so that SDR equipment facilitates interoperation between different radio access systems and the various types of reconfigurable platforms available. This paper gives an overview of the influencing factors and provides some direction and recommendations of how compliance can be achieved. This includes a description of the approach that is taken by the E2R project and that can be applied to ensure compliance between different adaptive communication platforms.
Configuration Control Mechanisms in Reconfigurable Radio Equipment (paper) Gultchev, S., K. Moessner (Centre for Communication Systems Research, University of Surrey Guildford)
SDR technology is advancing in new stage where specification and standardization efforts are eminent. This makes it an increasingly important technology for existing as well as future wireless technologies. These efforts however must not remain limited to individual pieces of equipment, but a consistent and verified specification for the whole communication chain is required. The functions and architecture facilitating reconfiguration in E2R [1] form a prime example. To be able to guarantee interoperability and cooperation between the different elements within such system, a detailed description of the requirements for equipment but also of the control operations that form and enable a reconfiguration process is needed. These specifications need to include descriptions of the actual module functionality as well as of the E2R management/ control sequences. The main requirements are towards compliance as well as towards software and (radio) configuration verification and validation techniques. This paper provides an overview of the requirements and describes examples of how interoperability in End-to-End Reconfigurable Systems can be achieved.
FP7 E3 Project Key Challenges (paper) Bourse, D., M. Muck, D. Bateman (Motorola Labs, Gif-sur-Yvette, Parc Les Algorithmes, France), W. Koenig, K. Nolte (Alcatel-Lucent, Germany), P. Martigne (France Telecom), I. Gaspard, E. Bogenfeld (Deutsche Telekom, Germany), N. Kiukkonen (Nokia, Finland), E. Buracchini (Telecom Italia Lab, Italy), E. Nicollet (Thales Communications, France)
This paper presents the ambitions and objectives of the FP7 End-to-End Efficiency (E3) project proposal. Building on the outcomes of the FP6 End-to-End Reconfiguration (IST- E2R) project [1], E3 is aiming at integrating cognitive wireless systems in the Beyond 3G (B3G) world, evolving current heterogeneous wireless system infrastructures into an integrated, scalable and efficiently managed B3G cognitive system framework from a technical, regulatory and business perspective. The cohabitation of multiple heterogeneous Radio Access Technologies (RAT) is studied with the objective to provide system design and management solutions based on Cognitive System principles; in this context, collaborative and autonomous decision making approaches are considered from both, the network and user terminal point of view. Additionally, related enabling technologies are developed, such as the Cognitive Pilot Channel. The prototyping effort will showcase the efficiency of the proposed solutions in a multi-technology environment.
Performance Evaluation of the Functional Description Language in a SDR Environment (paper) Zhong, S., C. Dolwin (Toshiba Research Europe Limited), B. Steinke, K. Strohmenger (Nokia Research Center)
In this paper we present and evaluate an XML based Functional Description Language (FDL) to communicate configuration information for Software Defined Radio (SDR) equipment. To demonstrate the feasibility of using FDL, we have implemented a proof-of-concept platform based on the Real-Time Research Platform (RTRP) and a Nokia 770 Internet Tablet. The platform has been designed to emulate an SDR terminal where the RTRP implements the functionality of a future reconfigurable SoC. To emulate the network an Open Mobile Alliance Device Mangement (OMA DM) server has been implemented on a laptop, while an OMA DM client operates on the Nokia 770. Both are linked via a WiFi connection. The proof of concept demonstrates the downloading of an FDL document describing the IEEE 802.11a RAT and its interpretation into a set of object codes and configurations for a DSP, FPGA and GPP. Two FDL files have been created to describe the IEEE 802.11a transmitter and receiver. The overhead for parsing the 802.11a transmitter and receiver FDL descriptions were measured. The reconfiguration overhead for deploying the whole 802.11a baseband RAT using the FDL language was evaluated.
Session 3.1
Use of Wavelet Techniques in Spectrum Holes Detection in Opportunistic Radio (paper) Thilakawardana, S., K. Moessner (Mobile Communications Research Group, CCSR, University of Surrey)
Opportunistic Radio (OR) systems make use of the availability of spectrum holes in the primary systems. In OR spectrum hole availability needs to be identified through spectrum sensing procedures. Apart from the sensing of the spectrum, OR must be capable of detecting the primary system and move out of the spectrum once the primary system requires the spectrum usage. Therefore spectrum sensing and detection needs to be performed efficiently for the successful deployment of an OR system. One way of identifying the spectrum holes availability is identifying power spectral density (PSD) and their power levels within a selected portion of the spectrum. The selected spectrum can be divided into multiple numbers of spectrum sub bands and power level of each sub band can de determined from the shape of the PSD of the selected spectrum. According to the PSD levels spectrum sub bands can be categorized as into black, grey or white spaces corresponding to high, medium and low PSD levels. White spaces are usually considered as spectrum holes that can be picked by the OR system for opportunistic spectrum usage.
A Study on Coexistence of WLAN and WPAN Using a PAN Coordinator with an Array Antenna (paper) Nakao, Y., K. Watanabe, R. Kohno (Graduate School of Engineering, Division of Physics, Electrical and Computer Engineering, Yokohama National University), T. Sato (Department of Information Network Engineering, Faculty of Knowledge Engineering, Musashi Institute of Technology)
Cognitive Radio can communicate with minimal interference by using the spectra which is allocated to primary radio systems. Two approaches to spectrum sharing by using cognitive radio have been considered. In this paper, the underlay approach is focused. This approach can be achieved by ultra wideband (UWB). In 3.1-10.6 GHz bands UWB transmission is allowed. However, in these bands, other licensed applications (e.g., IEEE 802.11a) are operating. Therefore, UWB system has some limits in the transmitted power to ensure a negligible impact in terms of interference. In this paper, we focus on the coexistence of wireless personal area networks (WPAN) and IEEE 802.11a for indoor environments. We assume WPAN as UWB system. We propose the access control which can avoid interference from WLAN by using an array antenna. An array antenna is equipped by PAN coordinator to use adaptive beamforming. When WPAN mitigates interference by time domain or space domain technologies, we evaluate each system's total throughput and interference by computer simulations. We show that these algorithms outperform the conventional method by decreasing interference and improving each system's total throughput.
Composition, Equivalence and Interoperability: An Example (paper) Kokar, M., L. Lechowicz (Department of Electrical and Computer Engineering, Northeastern University)
This paper describes an ongoing effort to use formal methods of software specification and refinement in order to achieve interoperability of Cognitive Radios. In particular, we are interested in the scenario in which two nodes negotiate the composition of software functionality from simpler components, including the ability to infer that the composed module has the same functionality as requested. We show examples of the use of the formal language (Metaslang) to express composition, refinement and abstraction. Moreover, we show that a formal reasoning system can infer the equivalence of two structurally different modules. We also discuss our current research directions towards solving the goal of representation and composition of behavioral (dynamical) models of radio components.
A Context Interpretation Framework for Cognitive Network Devices (paper) Sharma, H., P. Balamuralidhar (Tata Consultancy Services Ltd., Bangalore, Karnataka, India)
Application of Cognitive techniques is an upcoming paradigm in telecommunications, in which either a network or a radio can change its configurations and techniques, to communicate and manage efficiently in changing environment. Application of knowledge-based approach to embed computational intelligence in these network devices to achieve this object is of exploration by many researchers. In this paper we propose an architecture for reasoning and interpretation over information gathered in form of context data. A prototype was developed that uses certain knowledge management tools as its components. We present an overview of the prototype and further discuss some of the results. Certain deployment strategies and open issues are also discussed in this paper.
A Study on the Estimation of Traffic Quantity and MAC Protocol in Radio Wave Environmental (paper) Enda, K., R. Kohno (Yokohama National Univ., Yokohama, Japan)
In case of actualizing cognitive radio (CR) concept, it is significant the radio wave environmental monitoring (RWEM) which cognizes radio wave using situation of surrounding device. RWEM is composed of physical layer and MAC layer. In this paper, we focus on MAC layer because that its estimation leads to an increase of communication occasion. The plural terminals estimate the position of target, and estimate whether transmit or not. It enables to estimate traffic quantity of target. Furthermore, checking the transmission situation of each target and surrounding device, we judge whether contention base protocol or control base protocol and estimate target’s MAC protocol.
Session 3.2
Development of SDR Based Equipment with Channel Monitoring Function for Cognitive Radio (paper) Kashiki, K., T. Fujimoto, M. Nohara (KDDI R&D Laboratories, Yokosuka, Japan), T. Matsumura (Toyota InfoTechnology Center, Tokyo, Japan)
As one of research activities regarding the cognitive radio, we have developed the Software Defined Radio (SDR) equipment for the OFDM signal such as the WiMAX. We have also developed an equipment which has the capability to monitor the amplitude and phase spectra of the transmission path, by using functionality of the SDR. In this paper, we introduce the evaluation of its performance and the experimental results of the transmission channel monitoring. In addition, we have made analytical studies which can be obtained based on the propagation theory considering the path delay and path loss among multi-paths. From the experimental study and analytical one, it is concluded that the scheme proposed obtains superior estimation for the case of multi-path channel. The developed SDR-based equipment has the feature which is easily possible to provide the channel monitoring function without addition of hardware elements.
Implementation of a Cognitive Radio Modem (paper) Amini, P., E. Azarnasab, S. Akoum, X. Mao, H. Rao, B. Farhang-Boroujeny (University of Utah, Salt Lake City, UT)
Design and implementation of a cognitive radio modem on the Small Form Factor (SFF) Software Defined Radio (SDR) platform, provided by Lyrtech and Texas Instruments (TI) is reported. Filter- banks were used for spectrum sensing and this method is shown to exhibit superior performance in terms of the spectral dynamic range when compared to the conventional Fast Fourier Transform (FFT) techniques, i.e. periodogram method. To ensure reliability, a distributed sensing method is considered. Packet detection and channel equalization are performed using a cyclic preamble. A fractionally spaced equalizer is used for both channel and timing recovery. The different processing tasks are divided between a TI c64x+ DSP and a Xilinx Virtex IV FPGA while an ARM9 core is used for interfacing and running the Greenhills operating system. Measurement results from channel sensing are presented to show the high spectral dynamic range obtained using the filterbank sensing method.
A Wide Band Spectrum Sensing Approach With Agility and Low SNR Sensibility (paper) Ge, F., C. Bostian (Center for Wireless Communications, Virginia Tech)
Sensing-based opportunistic spectrum access is a critical component in cognitive radio applications. The first challenge is to design a signal detector that can quickly search through a wide bandwidth for vacant spectrum in order to establish a new channel. Further, the cognitive radio has to switch agilely to another channel when a primary user appears. Primary users’ signals may be at a very low SNR and operate dynamically. Cyclostationary features detection is attractive for detecting primary users, since it is known to be adept at signal detection and classification with high sensitivity. However, a key issue of cyclostationary signal analysis is the high computational complexity arising from the large number of required complex convolution operations. In addition, the computation requirement increases significantly in proportion to the bandwidth to be covered. These factors limit receiver agility and sensitivity. To reduce the computation requirement, we use parallel computing in cyclostationary feature analysis running on a Cell Broadband Engine (Cell BE), which has a peak performance exceeding 200 GFlops for single precision floating point operation. Our test system is a Universal Software Radio Peripheral (USRP) board connected to a Cell BE powered PlayStation 3 with GNU Radio installed. Our cyclostationary feature computation exploits all six usable Synergistic Processing Elements in the PlayStation 3. The signal detector is implemented in our Public Safety Cognitive Radio node following a newly designed spectrum sensing scheme that incorporates channel monitoring, data transmission, and dynamic spectrum switching. During the data transmission, a channel search is continuously running to collect available spectrum and updating the most recent spectrum in a database, which will be used for dynamic spectrum switching. The test frequency range covers the VHF TV band and the 700 MHz Public Safety band.
A 100 MHz – 2.5 GHz CMOS Transceiver in an Experimental Cognitive Radio System (paper) Cafaro, G., N. Correal, D. Taubenheim (Motorola, Plantation, FL), J. Orlando (Motorola, Schaumburg, IL)
This paper describes a fundamentally flexible low power 90 nm RFIC transceiver chip that has been used in a cognitive radio demonstration. Novel circuit architectures have been applied to the 90 nm CMOS RFIC to overcome problems that have encumbered wideband transceivers in the past. Flexible programming allows the RFIC to process signals of multiple wireless protocols from 100 MHz – 2.5 GHz with channel bandwidths from 8 KHz to 20 MHz. The cognitive radio demonstration unit integrates the RFIC, digital signal processing, a cognitive communication stack, and an embedded Linux operating system. A PC controls the unit and provides a graphical user interface, including visualization of the spectral sensing, signal detection, and dynamic frequency allocation that is taking place in the units.
Genetic Algorithm Approach for the Decision-Making Framework in Opportunistic Radio (paper) Chantaraskul, S., D. Thilakawardana, S. Thilakawardana, K. Moessner (Centre for Communication Systems Research (CCSR), University of Surrey, Guildford, Surrey, United Kingdom)
Cognitive Radio (CR) introduces the idea of system awareness and intelligent adaptability to advance Software- Defined Radio (SDR). This has opened up an attractive aspect in the development of an efficient and intelligent optimization based on various soft-computing techniques. In this work, the focused radio concept is termed as Opportunistic Radio (OR), which is the narrower definition of CR considering solely the knowledge of spectrum awareness. The main concern of OR in here is the development of the decision-making framework and its approach. The method used here is the optimization based on Genetic Algorithm (GA). The paper presents the design of the OR decision-making framework with an implementation of multi-objective decision making using GAs.
Session 3.3
Dynamic Spectrum Access Assessment in Cognitive Radios (paper) Aguayo Gonzalez, C., J. Reed (MPRG, Wireless@Virginia Tech)
The opportunistic utilization of unused spectrum provides Cognitive Radios (CR) with great performance improvements and enables new applications and services. This Dynamic Spectrum Access (DSA) behavior, however, introduces sev- eral challenges that must be overcome before CR technology can be widely deployed. One of these problems is the assessment of DSA compliance with regulations and policies. Traditional techniques used to validate and evaluate the per- formance of communication systems are no longer sufficient due to the extreme flexibility and independent decision- making inherent to CR. New test and analysis methods need to be developed to assess the spectrum access behavior of CR and safeguard the harmonious interaction with other CR and legacy systems. In this paper, we propose a test strategy for assessing the DSA behavior in CR. Candidate measurement techniques, operational scenarios, and test beds to assess the correct functionality and performance of CR are presented. This paper explains the application of these techniques in the context of a CIREN prototype, an ongoing development effort at Virginia Tech as part of the Smart Radio Challenge. The techniques here described provide an initial set of guidelines for regulatory bodies and radio developers to assess the DSA capabilities of CR devices.
Low Complexity Architectures for Multi-Carrier Cognitive Radio Design (paper) Jaeger, D., M. Vondal, P. Ring (Northrop Grumman IT/TASC, Chantilly, VA), f. harris (San Diego State University)
The adaptability of cognitive radio enables the development of systems with several favorable capabilities that permit the opportunistic use of spectrum while maintaining cooperative coexistence in densely occupied environments. Many desirable applications of this communications technology favor a stringent minimization of the implementation resources required, even at the cost of limiting the full best- case performance or flexibility. This paper examines an approach to implementing a low-complexity, multicarrier, cognitive radio based on an adaptive sparse realization of an Interpolated Tree Orthogonal Multiplexing (ITOM) structure, along with several additional modem resource optimizations. The performance and cost tradeoffs of this unique configuration are discussed with emphasis on performance impacts.
A Public Safety Cognitive Radio Node System (paper) Le, B. (Cognitive Radio Technologies, Lynchburg, VA), P. Garcia, Q. Chen, B. Li, F. Ge, M. ElNainay, T. Rondeau, C. Bostian (Center for Wireless Telecommunications, Virginia Tech, Blacksburg, VA)
This paper gives a complete map of building a cognitive radio. It goes through architecture definition, functional block building, system integration, and finally to a fully- functional CR node prototype that can be directly packaged for application use. In our CR solution, a platform independent CR system architecture is defined with a software algorithm package called a cognitive engine (CE) with a general radio interface. Within the CE different functional modules are defined to realize cognitive capabilities including awareness, reasoning, solution making and optimization, and adaptive radio control. Based on this general CR solution, we present an application specific CR node prototype for public safety communication interoperability.
International Collaboration for a Cognitive Radio Testbed (paper) Rondeau, T., K. Nolan, L. Doyle (CTVR, Trinity College, Dublin, Ireland), C. Doerr, D. Grunwald (University of Colorado, Boulder), G. Minden, J. Evans (The University of Kansas), D. Raychaudhuri (Rutgers University)
With the constant advances in cognitive radio technology, there is a developing need for proper testing facilities. This paper introduces efforts to bring together research and development of cognitive radio, dynamic spectrum access (DSA), and software defined radio systems to enable testing in real-world environments, and to develop applications for these emerging systems. Using licensed test spectrum available to CTVR in Ireland, we propose a flexible, extensible cognitive radio platform designed to interface with different SDR, sensing, learning, and cognitive algorithms. The testbed will accelerate research and development as well as facilitate direct comparison of systems and algorithms to advance the knowledge and science of cognitive radio.
Session 3.4
Initial Design of a Cognitive Engine for MIMO Systems (paper) Volos, H., C. Phelps, R. Buehrer (Mobile and Portable Radio Research Group (MPRG), Wireless@Virginia Tech)
Multiple-Input-Multiple-Output (MIMO) techniques can provide significant performance enhancements in wireless communication systems. However, MIMO techniques (which include transmit diversity, beamforming, and spatial multiplexing as basic classes) exploit the channel in different ways. Thus, given a specific channel realization, these techniques, combined with modulation and coding, make the selection of an “optimal” solution a difficult task. To address this problem, we, propose the use of a cognitive engine to learn the relationship between the channel observables and the available MIMO/modulation/coding techniques. The overall approach is presented along with results of a partial implementation based on the genetic algorithm. We also provide a discussion of future work.
On The Performance of Wideband OFDM System in the Presence of Interference from UWB Systems (paper) Sodeyama, K., R. Kohno (Graduate School of Engineering, Division of Physics, Electrical and Computer Engineering, Yokohama National University), K. Ishibashi (Department of Electrical and Electronic Engineering, Faculty of Engineering, Shizuoka University)
Ultra wideband (UWB) radio communication has gained much attention such as a future radio communication technology. UWB radio devices must equip the interference mitigation technology since the radio band of the UWB radio systems overlaps that of other radio systems such as worldwide interoperability for microwave access (WiMAX) and 4th generation mobile cellular systems (4G). In this paper, the performance of wideband systems using OFDM over the coexistence environment is analyzed. In order to analyze the interference mitigation capability of low duty-cycle (LDC) protocol with impulse-based UWB radio system (LDC-UWB) Mutual collision probability between wideband OFDM systems and LDC-UWB systems is investigated and two state Markov collision model is proposed. Moreover, the frame error rate (FER) of wideband OFDM systems is discussed by using computer simulations.
Practical Signal Detection and Classification in GNU Radio (paper) O'Shea, T. (NC State University), H. Ebeid (University of Texas), T. Clancy (Department of Defense, College Park, MD)
This paper selects a number of effective, general methods for enabling signal detection, estimation, and classification needs for cognitive radio. Implementations of algorithms such as these are of key importance to Dynamic Spectrum Access (DSA). These algorithms are decomposed into logical blocks and then implemented in reusable GNU Radio signal processing blocks. These blocks are then demonstrated in an example GNU Radio application running in a Linux environment, using a Universal Software Radio Peripheral (USRP) as a radio frontend. A second USRP on an unconnected host computer is used to generate the relevant test signals used for training and detection/classification trials. A key advancement presented in this work is application of these algorithms to real-world signals input from an RF frontend, rather than ideal signals generated in MATLAB. We show that work is needed to normalize the output of the USRP to make signal detection and classification more robust.
Session 3.5
Reasoning Over Temporal Relations in a Cognitive Radio System (paper) Kovarik, V. (Harris Corporation, Melbourne, FL)
Understanding and reasoning over time is a critical enabling technology for intelligent machine behavior. Actions, states, and observed events can be modeled within the context of temporal events and their relationships. This enables the construction of temporal patterns that may be used by cognitive radio systems to proactively adapt and reconfigure themselves based on situational state. By providing a common temporal reference system, experiential knowledge can be shared between radio systems through the abstraction and propagating temporal patterns. Temporal reasoning can also be used to extend the robustness of radio environment maps. This paper explores qualitative and quantitative temporal reasoning within a radio system. A key aspect is a compact representation and efficient computation of transitive relationships within a digital processor.
A Subspace-Based Method for Spectrum Sensing (paper) Wagstaff, A., Merricks, N. (Mass Consultants Ltd., St. Neots, Cambridgeshire, UK)
A subspace-based method for gaining knowledge of the quality and usage of the spectrum is presented. The method separates so-called ‘structured’ and ‘unstructured’ components of a signal as determined by the eigenvalue decomposition. These components may be cast as carrier power and interference plus noise power (interference temperature), thus providing an estimate of the quality of a piece of spectrum even in the presence of incumbent services. Furthermore, the method may be extended to yield a unique signature for many different modulation types. Combination with a neural network leads naturally to a robust modulation recogniser which has been demonstrated on a spectrum analyser platform. Some applications for the technique are discussed.
A Signal Identification Application for Cognitive Radio (paper) Gorcin, A. (University of South Florida, Tampa, FL), B. Thiagarajan (Anritsu Co., Morgan Hill, CA)
One of the most important aspects of cognitive radio (CR) is that it proposes methodologies to increase current spectrum efficiency. One way that should be followed for this purpose is let the secondary users use the unused parts of the spectrum for a given geographical space, at a certain time. This requires a certain level of knowledge on the characteristics of the communications in the geographical area of interest. If the signal types and communication technologies existing in the area are identified, then it will be possible to determine how to let the secondary users communicate through the medium in a safe, reliable way with high QoS (Quality of Service) and, without interfering and harming the primary users’ communication. Secondly, if the signal type of the primary user is known, alternative methodologies can be applied to allocate the secondary user. For instance, if the primary user’s signal has the frequency hopping property, allocation of secondary user can be done accordingly. Finally, communication regulation commissions have regulations on some of the frequency bands indicating the type of the signal for that band. Intruding signals, which are not expected in the frequency band, can also be identified using signal identification techniques.
General Radio Interface Between Cognitive Algorithms and SDR Platforms (paper not available) Le, B. (Cognitive Radio Technologies, Lynchburg, VA), T. Rondeau, C. Bostian (Center for Wireless Telecommunications, Virginia Tech, Blacksburg, VA)
In cognitive radio (CR) systems, an interface is needed to convey information between the cognitive, application algorithms (i.e., the cognitive engine (CE)) and the supporting radio platform. In this paper, we explicitly define such an interface as a set of software functions, documents, and additional application tools required for the CE to recognize, configure and control the radio platform. In the paper we describe how the radio system is represented to the CE, how the CE represents generic waveform parameters, and how platform independent concept is implemented in the interface design for the CE to control different radios.
SDR Multistandard Basestation as a Key to Future Cognitive Radio Networks (paper) Koenig, W., K. Nolte, T. Loewel, A. Pascht (Alcatel-Lucent Deutschland)
Flexibility of established RAN architectures is limited due to missing standard/frequency band adaptability of the infrastructure to the environment. There are no means to adapt the RAN dynamically to the actual mix of terminals within a cell and to changing traffic demands e.g. caused by extraordinary events e.g. such as large sport events. Furthermore deployed terminals need to support a multitude of existing radio standards. This leads to longer time to market, higher complexity and shorter battery lifetime of the terminals. In this contribution a concept, partly developed within the E2R2 Project [1], a concept on Cognitive Radio is introduced that shall overcome these restrictions in a longer term. Exploiting the capabilities of SDR base stations a RAN is designed where the infrastructure adapts itself, i.e. autonomously, to offer the most appropriate mix of RATs according to e.g.: requested bearer services (bandwidth, QOS), capabilities of the mobiles within the cell (supported RATs, frequencies), available resources (spectrum, platform).
Session 3.6
Tests and Trials of Software-Defined and Cognitive Radio in Ireland (paper) Nolan, K., P. Sutton, T. Rondeau, L. Doyle (Centre for Telecommunications Value-Chain Research (CTVR) at University of Dublin)
This paper firstly describes the non-contiguous and reconfigurable orthogonal frequency division multiplexing (OFDM) system designed by CTVR. This was tested April in Dublin, Ireland, using licenced spectrum in the TV and microwave frequency bands. One of the outcomes of these trials, namely the effect of non-contiguous OFDM on the ability to achieve OFDM frame synchronisation at the receiver is presented in this paper. It is shown that frame synchronisation is feasible even when a primary non-cooperative user is sharing that same channel as the secondary opportunistic user.
Synthetic Symmetry in Cognitive Radio Networks (paper) Neel, J. (Cognitive Radio Technologies, Lynchburg, VA)
In [1] we introduced distributed non-cooperative dynamic frequency selection (DFS) algorithms which use only locally available information but achieve performance equivalent to centrally planned omniscient algorithms. These algorithms require the network to satisfy a condition termed Bilateral Symmetric Interference (BSI). While BSI holds between pairs of equal-power devices for most waveforms, establishing the existence of BSI across networks is difficult. In this paper, we show how to establish BSI in infrastructure and ad-hoc networks, in networks employing power control, and in networks which prioritize the performance of different users. When these techniques are combined with similar techniques developed by CRT for multi-carrier multi-antenna systems, most networks running most waveforms can achieve optimal allocations of layer 1 and 2 resources with low-complexity distributed algorithms using only locally available information.
Enhancing Spectrum Productivity Through Cognitive Radios Facilitating Cell-by-Cell Dynamic (paper) Thilakawardana, D., K. Moessner (CCSR, University of Surrey, Guildford, UK)
The cognitive radio technology has been identified as one solution to the apparent spectrum scarcity problem and the deployment of the cognitive radios in a particular cell at a given time depends on the availability of low priority spectrum opportunities. Network operators can generate such opportunities by allocating the spectrum dynamically on a cell by cell basis, considering spectrum as a function of time and space. The cell-by-cell dynamic allocation problem is considered as a NP hard class combinatorial optimisation problem and is very hard to solve by conventional optimisation techniques. Therefore, a genetic algorithm assisted method is proposed in this paper for the cell-by-cell dynamic spectrum allocation. A system level simulator referred “GENEDYSA” has been developed for dynamic spectrum allocation and also for comparison with fixed spectrum allocation scheme. The new scheme outperformed the conventional method in terms of spectral efficiency in both uniform and non-uniform traffic conditions.
A Radio Reconfiguration Algorithm for Dynamic Spectrum Management According to Traffic (paper) Trogolo, A., P. Goria, E. Buracchini (Telecom Italia S.p.A., Via G. Reiss Romoli)
The deployment of different RATs (Radio Access Technologies) that coexist temporally (i.e. at the same time) and geographically (i.e. on the same area), gives the opportunity to network operators to jointly manage the resources, in order to adapt the network to the behavior of the traffic and to globally maximize the capacity. For instance, in a certain geographical area (e.g. a city), it could occur that the offered traffic is not uniform in time and in space. In addition, in case of deployment of two or more RATs in the same area, the traffic offered to each deployed RAT could be differently distributed in time and space with respect to the traffic offered to the other deployed RATs. This paper focuses on this dynamic context, describing a new algorithm for the Radio Resource optimization to be used in a network deployed with Reconfigurable Base Stations. The aim of the new algorithm is to give network operators a mean for optimally managing the radio and hardware resources among different RATs and increasing the overall capacity of the whole network. In the paper some preliminary performance results obtained by means of simulation are also presented.
High Contribution Node Selection for Cognitive Radio Networks (paper) Yasuda, H., T. Fujii (AWCC, The University of Electro-Communications: Chofu-shi, Tokyo, Japan)
In this paper, we consider the secondary multi-hop cognitive radio networks under the existence of the primary system. In order to support a fluctuated primary interference within the networks, we propose a method to select high contributing relay nodes by using a contribution ratio derived by using the balance of the number of hops of the route request packet (RREQ) and that of the route reply packet (RREP) during the initial route establishment. The selected node is decided in each node by comparing the total number of hops of RREP and RREQ from each transmitter with the number of minimum hops of the route in the initial route plus some margin. By using the proposed method, we can select the appropriate nodes for maintaining the secondary networks.
Session 4.1
In-Band Wireless Backhaul Using SDR for Rural Cellular Systems (paper) Cabrera-Mercader, C., L-W. Chen, B. Fallik, S. Hu, J. Chapin (Vanu, Inc., Cambridge, MA)
This paper describes an SDR-based wireless backhaul system for a cellular radio access network. Backhaul is the data connection between base stations in the field and the operator’s switch or network. In-band backhaul is a wireless data link that uses the cellular spectrum already licensed by the operator, as opposed to licensed microwave or unlicensed spectrum. The innovative feature of the Vanu in- band backhaul system is using SDR to support both cellular service to mobiles and backhaul communications simultaneously on shared processor, radio and antenna resources. No additional hardware is needed at most sites for the backhaul beyond that already installed for the cellular base station. We use an IDEN radio access network as a concrete example, and present results from proof of concept field trials of the backhaul system.
Software Defined Receiver for Broadcasting Systems for Automotive Applications (paper) Sliskovic, M. (Harman/Becker Automotive Systems, Karlsbad, Germany)
Based on software defined radio technology, automotive receiver for three broadcasting systems has been developed. In this paper, an overview of the receiver architecture is given, and performance improvement achieved through utilization of digital signal processing methods is discussed. Two RF paths are implemented, which enables us to implement and test different diversity techniques. The mode of operation is programmable, and can be set through a control interface. The signal is converted into digital domain at IF level and digital signal processing algorithms are used for further processing. Utilizing programmable and software reconfigurable hardware, receiver for multiple standards and different standard variations worldwide can be implemented on the single hardware platform. Receivers for AM, FM and weather band broadcasting systems have been developed, and work on receivers for further waveforms is in progress.
High-Assurance SDR-Based Avionics RFID System (paper) Li, M. (Boeing Phantom Works, Seattle, WA), R. Falk, F. Kohlmayer, A. Köpf (Siemens AG Corporate Technology, Munich, Germany), R. Poovendran (University of Washington, Network Security Lab, Seattle)
This novel architecture supports various future eEnabled airplane applications based on RFID technology. As RFID readers and wireless communication equipment is installed on-board of airplanes, it has to support a manifold of different wireless communication standards. The flexibility offered by Software Defined Radio (SDR) plays here an essential role. The security solution concept identifies the security building blocks needed to protect the SDR-based avionics RFID system.
Session 4.2
Constrained Beamforming for Space GPS Navigation (paper) Brown, A., B. Mathews (NAVSYS Corporation, Colorado Springs, CO)
NAVSYS has developed a prototype for a flexible, high-performance Space-based Software GPS Receiver (SSGR) to demonstrate the next generation of tracking and navigation capabilities for space applications. Based on a Software Defined Radio (SDR) approach, the SSGR will provide an integrated precision navigation and attitude determination solution for space applications. In order to support GPS signal tracking in the space environment, a constrained beamforming algorithm tailored to the space environment has been developed that will allow satellites to track weak GPS signals even in very close proximity to other GPS satellites. In this paper we present the theoretical development of this algorithm, details of its deployment on the SSGR, and test results using the NAVSYS Advanced GPS Hybrid Simulator. The ability to track low power GPS satellites in the presence of much stronger GPS signals will extend the use of GPS for precision navigation and timing, particularly for high altitude space missions (above the GPS satellite constellation). With this capability, the SSGR will be suitable for supporting multiple space missions including GPS metric tracking during launch, orbit determination during transfer to geostationary orbits, and high accuracy navigation, attitude control, and timing. The flexibility of the SSGR design will allow it to be reprogrammed for use in launch and orbit entry, station keeping, and autonomous orbit estimation applications.
Cognitive Radio Implications for Public Safety Communications (paper) Cook, P. (HYPRES, Inc., Elmsford, NY, USA), Hope, S. (Orange Labs R&D UK Ltd, Bristol, UK)
The Public Safety community is caught between two cross-currents. On the one hand they have a need for more spectrum, significantly enhanced communication of data, economies of scale associated with volume production, and information technology resources to better support first responders. On the other hand their requirements for area coverage, reliability, and response-time characteristics are met by their existing equipment, but exceed that currently available in commercial systems. This problem has considerations in political, regulatory, technological, operational, and business/economic domains. While Cognitive Radio has much to offer to satisfy those needs, there has been a notable lack of consensus on many of the issues associated with spectrum allocation, architecture, and implementation. This paper provides a conceptual framework to aid in understanding the problems, and examines the current state of progress in fulfilling the needs and meeting the requirements identified above. It also reviews the concept of the “Super Base Station”, previously introduced as “Network Oriented Base Station”,in a facility that combines extremely high radio frequency performance with Software Defined Radio and Cognitive Radio capabilities to enhance the options available to system architects.
SDR at Astrium - Part II: From Defence to Civil Applications (paper) Sturman, T., M. Bowyer, N. Petfield (Astrium Limited, Portsmouth, Hampshire, UK)
High level aspects of security and Information Assurance (IA) in relation to Software Defined Radio (SDR) are raised in this paper. This paper forms Part II of a two-part series which describes some of the SDR work undertaken at Astrium. Astrium have been involved in SDR for about ten years; part of this effort has culminated in the generation of the UK`s military satellite communication (MILSATCOM) SDR modem, the Paradigm Modem (PM) – the first production MILSATCOM SDR modem of its sort in Europe. A particular emphasis is placed in this paper on some of the security design issues relevant to TETRA (TErrestrial Trunked RAdio) which is a digital trunked radio system that is very popular with European emergency services. Some security features of TETRA are considered with a view to address pertinent issues for the incorporation of one of Astrium`s commercial-off-the-shelf (COTS) SDR platforms in the rapid resolution of a civil crisis requiring international support.
SDR at Astrium - Part I: Space and Aviation (paper) Sturman, T., M. Bowyer, N. Petfield (Astrium Limited, Portsmouth, Hampshire, UK)
The Paradigm Modem (PM) is a Secure SDR platform based on the SCA (v2.2) and developed for the UK`s Military Satellite Communication (MILSATCOM) service provision for Skynet 5. The application of derivatives of the PM technology base for MILSATCOM, Space and Aviation is considered in this paper. Some essential background to Astrium and its association with SDR for a period of ten years is given. In the context of Space-based communications, the optimal and unconnected use of the four principal space orbits is a key motivation; examples of SDR for Space applications are provided. Astrium have been considering the utilisation of their SDR platforms for Airborne communications, specifically for supporting unmanned aerial vehicle (UAV) communications; an example of the application of SDR for Aviation is provided. SDR`s flexibility at tactical communications optimised to scenario and channel conditions can be extended further to facilitate the efficient use of hybrid SATCOM Orbits, Services and Applications. In the longer term, SDR will enable SATCOM evolution to the future vision of Network Enabled Capability (NEC) Nodes.
Updates to the NASA Space Telecommunications Radio System (STRS) Architecture (paper) Kacpura, T. (ASRC Aerospace, Cleveland, OH), L. Handler, J. Briones (NASA Glenn Research Center, Cleveland, OH), C. Hall (Analex Corporation, Cleveland, OH)
This paper describes an update of the Space Telecommunications Radio System (STRS) open architecture for NASA space based radios. The STRS architecture has been defined as a framework for the design, development, operation and upgrade of space based software defined radios, where processing resources are constrained. The architecture has been updated based upon reviews by NASA missions, radio providers, and component vendors. The STRS Standard prescribes the architectural relationship between the software elements used in software execution and defines the Application Programmer Interface (API) between the operating environment and the waveform application. Modeling tools have been adopted to present the architecture. The paper will present a description of the updated API, configuration files, and constraints. Minimum compliance is discussed for early implementations. The paper then closes with a summary of the changes made and discussion of the relevant alignment with the Object Management Group (OMG) SWRadio specification, and enhancements to the specialized signal processing abstraction.
Radiation Effects on Advanced Microelectronics from the Space and Nuclear Weapon Generated (paper) Hughes, B.F., J.J. Sheehy (Amtec Corporation, Huntsville, AL), R. Ecker, R. Hightshoe (Rockwell Collins, Cedar Rapids, IA), A. Corder, T. Ooi (Missile Defense Agency, Huntsville, AL)
This paper addresses radiation response issues associated with the deployment of Software Defined Radio (SDR) technology in natural space and nuclear weapons effects environments. This paper addresses the impact of these environments with respect to the electronic component technology likely to be employed in SDR applications along with a discussion of likely mitigation strategies. Dose rate, total ionizing dose (TID) and neutron effects will be considered for the nuclear weapons environment. The natural space radiation environment assessment will be based on trapped radiation in the van Allen belts, solar particle flux, and galactic cosmic rays and will consider TID and single-event effects (SEE). In terms of device response, exposure to either of these environments may cause parametric shifts in electrical performance, upset, latchup or possibly functional failure of the device under consideration. Because SDRs are likely to make use of state-of-the-art electronics such as FPGAs, DSPs, microcontrollers, SRAMs, SDRAM, and Flash Memory, special attention will be given to these technologies. The particular vulnerabilities of each of these device types with respect to radiation effects will be reviewed and discussed.
Session 4.3
Evaluation of Multilink Communication Method Collaborating with Resource Management Function (paper) Shiba, H, K. Akabane, M. Matsui, K. Uehara (NTT, Yokosuka-shi, Kanagawa, Japan)
Many wireless systems, such as cellular and wireless LAN systems are now in use and are being standardized. Also, wireless services, such as telephone and video streaming, have diversified as wireless systems technology has advanced. Autonomous adaptive base stations (AABSs), which switch functions depending on the availability of the wireless system and the quality of service, are advantageous in this environment. We propose a multilink (ML) communication method that collaborates with AABS’s resource management function to use frequency and the hardware resources of AABSs more efficiently and more flexibly. We demonstrate the effectiveness of the proposed ML communication method using a computer simulation.computer simulations.
From Simulation to Demonstration – A SDR-based Multi-Mode PHY Layer Testbed (paper) Huang, L., K. Zheng, G. DeCarreau (Orange Lab, Beijing, China), H. Cao, G. Li, Z. Man, Z. Yan, H. Zeng (Beijing Univ. of Posts and Telecom, Beijing, China)
This paper presents a SDR-based multi-mode testbed being developed by Orange Lab Beijing and BUPT, which consists of the Universal Software Radio Peripheral (USRP) boards and the PC-cluster. GNU Radio, C++ / IT++ programming and MPI parallel computing framework are used to make the testbed easy to be developed. So the fast prototyping is possible. The purpose of this testbed is to validate the algorithm performance in realistic channels and in the presence of implementation impairments. Now the TD-SCDMA 64 kbps / 384 kbps links and a 2x2 MIMO- OFDM system are already built in this multi-mode PC- Cluster SDR platform. The system performance, SNR, BLER, MIMO channel fading and correlation matrix etc can be shown in graphic monitor windows in real-time.
Hardware Implementation of a Versatile Low-Cost Mixed-Signal Platform for SDR Experiment (paper) Barrandon, L., G. Baldwin, R. Farrell, G. Corley (Institute of Microelectronics and Wireless Systems, Centre for Telecommunications Value-Chain Research, NUI Maynooth, Ireland)
This paper presents the design of a reconfigurable mixed- signal platform used in the Software Defined Radio context. It is a single board part of a pre-existing modular system operating from 1.6 to 2.5 GHz that supports GSM1800, DCS1800, PCS1900, UMTS-FDD, UMTS-TDD and 802.11b standards. Its purpose is to facilitate configuration and data exchange between a computer and an RF transceiver. Technical choices, design and overall performances of the prototype are discussed.
Computing Resources in Flexible Radio Environments (paper) Salazar, J., V. Marojevic, I. Gomez, A. Gelonch (Radio Communication Research Group, Universitat Politècnica de Catalunya, Barcelona, Spain)
It is well known that in future mobile communication systems the variations over the communication parameters - channel characteristics, radio resources availability, user service requirements - will be more significant for satisfying the capacity demands due to the coexistence of different radio access technologies within a heterogeneous environment. Software Defined Radio devices are suitable for meeting such demands by the means of software and reconfigurable hardware platforms. The need of a dynamic management of resources is crucial for the success of such implementation due to the relationship between the radio resources and the resources in terms of processing power and memory. This work introduces the concept of resource management framework which includes computing resource management cooperating with the radio resource management strategies. The goal is to dynamically seek to minimize computing costs but assuring certain Quality of Service constraints.
"Smart Carpet" – A Distributed Cognitive Radio (paper) Reichart, S. (Air Force Research Laboratory), B. Youmans (PAR-Rome Research Corp.)
Electromagnetic threats exist in many forms on both the battlefield and at home. Current detection and countermeasure systems typically target only specific threats and perform limited actions. Furthermore, some countermeasure systems easily reveal themselves or cause disruptions of tactical systems. The need exists for a field-reconfigurable, distributed cognitive radio system that has the capability to integrate the communication system with a countermeasure system. The Information Connectivity branch of Air Force Research Laboratory (AFRL) (Rome Site) has led programs in Software Radio Technology and has used the Software Radio Development System (SoRDS) to developed techniques for “Smart Radios”. The AFRL team has developed a field deployable, distributed cognitive radio system for signal detection, signal identification, and emitter geo-location.
Session 4.4
Wideband Radar Adaptive Beamforming Using Frequency-Domain Derivative Based Updating (paper) Mathews, B., A. Brown (NAVSYS Corporation, Colorado Springs, Colorado), J. Griesbach (SAIC, Colorado Springs, Colorado)
This paper details an advanced wideband adaptive beamforming algorithm for multi-channel radar systems that is currently in the process of being implemented in an FPGA. This approach models the entire frequency spectrum and linearly tracks statistical source covariance changes over frequency. achieved using a technique called derivative based updating (DBU). The novel aspect of this algorithm is its application in the frequency domain to track jammer source variations in angle as a function of frequency. This algorithm is compared with a traditional subband ECCM technique for multiple jamming scenarios. Front-end array hardware recommendations are also considered in this presentation. The baseline front-end architecture involves use of non-overlapping subarrays to reduce the number of digitized channels. An overlapping architecture is recommended that gives greater flexibility and control over spatial ambiguities. With wider operating bandwidths come increased processing demands on the beamforming hardware. By taking advantage of the increasing processing power available in commercially available Field Programmable Gate Arrays (FPGA), and with the increasing speed of modern digital interfaces, it is becoming increasingly feasible to perform wideband adaptive processing in the digital domain, where advanced beamforming techniques can be exploited to realize performance and flexibility benefits of a portable firmware-based implementation.
A Survey of Multiple Antenna TX-RX Methods for WIBRO/WIMAX (paper) Kang, S., S. Choi, J. Chung (The School of Electrical, Computer and Communication Engineering, Hanyang University, Seoul, Korea)
WiBro/WiMAX is an OFDMA-based multiple access service for wireless broadband multimedia environment. Multiple antenna system has been considered to increase the capacity, service area, and data rate for WiBro/WiMAX base station system. In this paper, we compare the methods for multiple antenna system of WiBro/WiMAX and show the performance benefits of various multiple antenna methods. We examine the space time transmit diversity (STTD) and spatial multiplexing scheme for WiBro/WiMAX. We first describe the signal modeling and operations for STTD, spatial multiplexing. Then we explain advantages and disadvantages in each method, to summarize the differences among the methods. We also demonstrate various simulation results to show the performances of STTD and spatial multiplexing which are compared in various communication circumstances.
Implementation of a SDR-Based MIMO Evaluation Platform Supporting WIBRO/WIMAX (paper) Park, S., S. Seo, J. Chung, S. Choi (HY-SDR Research Center, Hanyang Univ., Seoul, Korea)
In this paper, we implement a MIMO Evaluation Platform with multimode functionality for SDR system. The presented platform contains PHY(Physical layer) including the baseband MODEM(modulation and demodulation) part with the MIMO and smart antenna functionality. The platform is designed to evaluate the performance of various MIMO detection scheme as well as smart antenna scheme utilizing the SDR technology. SDR technology enables a communication system to be reconfigured into MIMO or smart antenna mode through software downloads to the flexible hardware platform that is implemented using programmable devices. We first describe the operations and functions required by MIMO and smart antenna. Then we explain a design procedure and hardware implementation of the evaluation platform. We also demonstrate our experimental circumstance to show the performances of MIMO and smart antenna which are compared and verified with presented platform.
Smart Antenna APIs: From Concept to Practice (paper) Hyeon, S., J. Kim, S. Choi (HY-SDR Research Center, Hanyang University, Seoul, Korea)
The Smart Antenna Working Group of the SDR Forum is developing an application programming interface (API) supporting inter-operability and compatibility of various kinds of smart antenna systems operating in a SDR (Software Defined Radio) network following an open- architecture model. The Smart Antenna API consists of three components: (1) an SAControl Component, which is used for controlling the smart antenna system, (2) an SAAlgorithmDevice Component, which is used for executing various algorithms such as beamforming, DOA (Direction-of-Arrival) estimation, STC (Space Time Coding), channel estimation, spatial multiplexing, etc, and (3) an SASynchronnization Component, which is used for calibration. This paper introduces the Smart Antenna API, illustrating its use as a standard model and standard service in advanced wireless networks, and defining a roadmap for the API for additional standardization.
Session 4.5
Hardware in the Loop: A Development Strategy for Software Radios (paper) Azarnasab, E., P. Amini, B. Farhang Boroujeni (University of Utah, Salt Lake City, UT)
A framework combining DEVSJava simulation engine and MAT-LAB is developed to implement a network of cognitive radios while using the real hardware among simulated modems. The process starts with one node and uses simulation in different stages of the development as a test and measurement tool. Based on the progressive simulation based design and development, we start from simulation and substitute the models with real modules step by step to build a full functional modem. Afterwards, to develop the network of the cognitive radio modems, we deploy the available real modems with simulated primary and secondary users in a central simulation. To simulate the effect of the primary users on real modems, an arbitrary signal generator is used to emulate the transmitted signal of licensed users on the channel. Using this method, we are able to develop our cognitive network while we do not have enough hardware. One real node is integrated in our simulation which performers channel sensing and data transmission. When this node detects the presence of a primary user on its current working carrier, it moves to an unoccupied carrier.
Software Development Solutions for Multiprocessor and SoC Systems Used in SDR (paper) McClean, T., Hermeling, M. (Zeligsoft, Gatineau, QC, Canada)
The advances in system-on-chip (SoC) and multiprocessor platforms have made software development for these environments much more involved. Today’s platforms contain multiple processors, often from different classes (DSPs, FPGAs, GPPs and so forth), and each of these processors can contain multiple processing cores. The traditional approach used to develop software cannot address this complexity due to two major shortcomings. Firstly, it views the world as a single layer in a homogeneous environment or at most as an application layer deployed to some form of an execution environment layer. Secondly, the traditional approach uses a code-based development environment to develop the application layer, which provides the developer with no information about the overall system. This paper looks into why the traditional approach no longer suffices when developing software for complex platforms and what other technologies are available to bridge the gap.
Debugging Strategies for SCA Components and Waveforms (paper) Dietrich, C., D. Cormier (Wireless@Virginia Tech: Blacksburg, VA)
In order to diagnose errors in a communications system, an SDR developer must have a debugging environment that is able to send and receive known signals to various ports in a waveform, as well as assess the output response exhibited by components of interest. The developer must also be able to understand the effects of latency in his/her system These methods of diagnosis are illustrated using ALF, a free, open source graphical debugging environment that takes advantage of the SCA’s use of CORBA to connect to component ports within a running waveform. ALF is written in python for ease of development and maintenance. It includes several tools that can be used to monitor waveform performance and compare it with expectation. Users can develop and add their own tools to ALF as needed. Current tools include a software arbitrary waveform generator, a real-time spectrum and constellation plotter, and a signal sink. Provisions also exist for monitoring timing and determining latency throughout a waveform, enabling identification of components requiring buffering or optimization for real-time operation.
Testing and Measurement of Cognitive Radio and Software Defined Radio Transceivers (paper) Arslan, H. (University of South Florida, Tampa, FL)
This paper describes an overview of Software Defined Radio (SDR) and Cognitive Radio (CR) testing and measurement issues. Challenges, opportunities, short and long term goals, and a possible path towards achieving a flexible SDR/CR testing and measurement capability are discussed. Requirements and possible ways of introducing enhanced and multi-dimensional signal analysis capability, possible new performance measures for quantifying the quality of SDR/CR transceiver, signal intelligence and new ways of monitoring radio signals in multi-dimensional electrospace are also discussed briefly in this paper.
Design Abstraction Tool for On-Demand, Automated Radio Synthesis and Implementation of SDR(paper) Jaeger, D., P. Ring, M. Vondal (Northrop Grumman IT/TASC, Chantilly, VA), f. harris (San Diego State University, San Diego, CA)
The term Software-Defined Radio (SDR) refers to a class of radio devices that provide a flexible, generic hardware platform where the modulated waveforms, data format, and transport protocol are defined by configurable means, such as software and programmable logic. This configurability, if utilized, enables a radio to be modified quickly in the field to meet changing requirements or varying environmental conditions. The process of designing a specific implementation for such flexible radios, however, requires a large investment of time and effort by skilled design engineers who posses in-depth knowledge of both the signal processing and the development tools required to implement and optimize the software or logic for a given hardware platform. In this paper the authors discuss their efforts to create a tool that provides a new level of radio design abstraction – intended to provide an integrated toolset for the rapid development of new designs by an operator without an in-depth knowledge of communication theory. By raising the level of radio design abstraction and automating the process flow, this new tool enables designers to generate implementations for software-defined radios which can be quickly and easily adapted to changing signal environments and the requirements of specific systems and networks.
Session 4.6
SDR Signal Processing Distributive-Development Approaches (paper) Paniscotti, D. (VP SDR Products of PrismTech Corp., Burlington, Mass), Bickle, J. (Chief Scientist SDR Products of PrismTech Corporation)
The implementation of Software Defined Radios (SDRs) involves the development of software on various signal processing environments including General Purpose Processors (e.g., Intel® XScale™, IBM® PowerPC®), Digital Signal Processors (DSPs ) (e.g., TI™, Analog Devices ) and Field Programmable Gate Arrays (FPGAs) (e.g., XILINX, Altera). JTRS Software Communications Architecture (SCA) [1,2] based waveform components developed for GPPs typically communicate with each other using CORBA® middleware, generally use the C++ language in their implementation and are layered on various POSIX®- compliant Real-Time Operating Systems (RTOS) (e.g., GreensHill®, VxWorks®, LynxOS®) as described by the SCA Application Environment Profile (AEP). However, this approach has not historically been used when such waveform components are targeted for DSPs. The paper will discuss past, current, and advanced approaches used in the development of these waveform components in non-GPP based applications.
An Open Architecture SCA Reference Platform (paper) Murotake, D. (SCA Technica, Inc., Nashua, NH)
Software defined radios (SDR) are capable of supporting a number of radio technologies (waveforms) using software downloads. For each waveform, a “reference waveform” is developed and published as a “standard” for deployment on different radio platforms. : At present, each “reference waveform” each has a unique hardware reference implementation and waveform architecture. Thus each waveform has a unique Hardware Abstraction Layer (HAL), Board Support Package (BSP) and Operating Environment (OE). Furthermore, each Reference Waveform may employ a unique waveform component architecture, with control and and dataflow connections being made in a unique fashion. This stymies attempts to create a unified, composable component architecture, or a Hardware Abstraction Layer (HAL), common to multiple waveforms. This paper explores the requirements and architecture of a proposed SCA 2.2.2 compliant Open Architecture Common Reference Platform, based on COTS commercial hardware and software components, which may be used to simplify the development and porting of future Reference Waveforms to SDR programs. Additionally, the paper examines the possibility of using the Common Interface Cryptologic Module (CICM) interface for the open architecture Type 1 Crypto Development Card.
Waveform Portability and Reuse Across Operating Environments: An Experience Report (paper) Bickle, J. (Chief Scientist SDR Products of PrismTech Corporation, Fort Wayne, IN)
In the past, there have been many papers discussing the proper separation or isolation of waveform implementations across varying SDR Operating Environments (OEs) such as the Software Communications Architecture (SCA) [1,2] OE (Core Framework (CF) Common Object Request Broker Architecture (CORBA®), and Portable Operating System Interface (POSIX®) Application Environment Profile (AEP)). Many of these papers also discuss the reuse and portability benefits reaped by such approaches. This paper presents an experience report on the application of such techniques to provide portability and re-use across disparate physical OE platforms. This paper describes how an SCA waveform model can be used to produce an SCA-compliant waveform implementation and then describes how the same waveform source code can be compiled and deployed across multiple processing environments with differing operating systems and middleware implementations. The result of this demonstration illustrates the reality that the source code is Real-Time Operating System (RTOS) and Object Request Broker (ORB) neutral. This paper also describes how the same waveform model can also be used to create an Object Management Group™ (OMG™) SWRadio [3] waveform implementation and how the same waveform logic (e.g., algorithms, coders, etc.) can be used across SCA and OMG SWRadio compliant waveform implementation.
Techniques and Recommendations to Improve Waveform Portability (paper) Macejak, S., D. Maldonado, J. Agniel (L-3 Communications Nova Engineering, Cincinnati, OH)
With the creation of the Software Communications Architecture (SCA) as part of the Joint Tactical Radio Systems (JTRS) program, the government has invested substantially to address the need for waveform portability. However, to date, the SCA has emphasized the software residing on a general purpose processor (GPP). The SCA specification does not adequately address the physical layer (PHY) waveform processing as the PHY implementation is typically accomplished in digital signal processors (DSPs) and field programmable gate array devices (FPGAs). A 2006 GAO assessment of the JTRS program cited unacceptably high porting costs and long porting schedules, indicating that the JTRS waveforms have yet to live up to the objective of highly portable, hardware-agnostic software applications. In this paper, however, we show through two case studies that the portability goals of the JTRS program are achievable. We address the importance of the waveform software architecture and the role of a Portability Toolkit in reducing waveform porting costs. We also identify the non-portable techniques that currently prevail in the industry. The recommendations presented here derive from our experiences with the Single Channel Ground-Air Radio System (SINCGARS) waveform, Wideband Network Waveform (WNW) OFDM PHY, and Soldier Radio Waveform (SRW).
A Workbench for Waveform Description Based SDR Implementation (paper) Kempf, T., E. Witte, V. Ramakrishnan, G. Ascheid (Institute for Integrated Signal Processing Systems, RWTH Aachen University, Germany), M. Adrat, M. Antweiler (Research Establishment for Applied Science (FGAN), Dept. FKIE/KOM, Wachtberg, Germany)
The use of multiple wireless communication standards in today’s communication networks opens completely new opportunities for future wireless communication, e.g. cognitive radios. However, current support for different standards requires implementation of redundant hardware within one handset. To cope with this issue, research in the field of Software Defined Radios (SDRs) aims at implementing the waveforms in software allowing reuse of shared hardware resources. Development of such SDRs is a challenging task as both software and hardware have to be developed under tough constraints of real-time processing, architecture and energy efficiency. To enable the three key properties of portability, interoperability and loadability, a concept has been proposed for a seamless SDR design flow in [1]. Key element of this concept is the orthogonalization of the waveform description, the mapping to an arbitrary hardware platform and the platform design. In this paper, a realization of the concept is introduced. The efficient design of the waveform application, hardware platform and application-to-architecture mapping enables fast exploration cycles during SDR development. The (semi-)automatic generation of the software and hardware implementations (on the basis of IP-blocks) enables designers to quickly verify, debug and test their design decisions in simulation models and on a prototype.
Software-defined radios have two requirements that are usually assumed to be diametrically opposed: high performance and portability. Standards such as the SCA focus on the second requirement for control logic, but SDR data paths in these systems tend to be optimized at the expense of flexibility. This is the result of two fundamental constraints on optimizing component-based SDR software in the traditional development lifecycle. The first is the ordering of the steps in the lifecycle itself: deployment information isn’t provided until after it’s needed. The second is the conflating of the component model contract with the code contract. This paper examines past practices. It then explains how to overcome these constraints to deliver components that are both portable and optimized for the context in which they’re used.
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