Software Defined Radio: Enabling Technologies(Wiley Series in Software Radio)

Software defined radio (SDR) is one of the most important topics of research, and indeed development, in the area of mobile and personal communications. SDR is viewed as an enabler of global roaming and as a unique platform for the rapid introduction of new services into existing live networks. It therefore promises mobile communication networks a major increase in flexibility and capability. SDR brings together two key technologies of the last decade - digital radio and downloadable software. It encompasses not only reconfiguration of the air interface parameters of handset and basestation products but also the whole mobile network, to facilitate the dynamic introduction of new functionality and mass-customised applications to the user's terminal, post-purchase. This edited book, contributed by internationally respected researchers and industry practitioners, describes the current technological status of radio frequency design, data conversion, reconfigurable signal processing hardware, and software issues at all levels of the protocol stack and network. The book provides a holistic treatment of SDR addressing the full breadth of relevant technologies - radio frequency design, signal processing and software - at all levels. As such it provides a solid grounding for a new generation of wireless engineers for whom radio design in future will assume dynamic flexibility as a given. In particular it explores * The unique demands of SDR upon the RF subsystem and their implications for front end design methodologies * The recent concepts of the 'digital front end' and 'parametrization' * The role and key influence of data conversion technologies and devices within software radio, essential to robust product design * The evolution of signal processing technologies, describing new architectural approaches * Requirements and options for software download * Advances in 'soft' protocols and 'on-the-fly' software reconfiguration * Management of terminal reconfiguration and its network implications * The concepts of the waveform description language The book also includes coverage of * Potential breakthrough technologies, such as superconducting RSFQ technology and the possible future role of MEMS in RF circuitry * Competing approaches, eg all-software radios implemented on commodity computing vs advanced processing architectures that dynamically optimise their configuration to match the algorithm requirements at a point in time The book opens with an introductory chapter by Stephen Blust, Chair of the ITU-R WP8F Committee and Chair of the SDR Forum presenting a framework for SDR, in terms of definitions, evolutionary perspectives, introductory timescales and regulation. Suitable for today's engineers, technical staff and researchers within the wireless industry, the book will also appeal to marketing and commercial managers who need to understand the basics and potential of the technology for future product development. Its balance of industrial and academic contributors also makes it suitable as a text for graduate and post-graduate courses aiming to prepare the next generation of wireless engineers.

Table of Contents:
List of Contributors xiii Foreword - by Dr Joseph Mitola iii xvii Abbreviations xix Biographies xxvii Introduction xxxv Part I: Perspective 1 1 Software Based Radio 3 Stephen Blust – Cingular Wireless 1.1 A Multi-Dimensional Model Sets the Stage 3 1.2 What is Software Based Radio 5 1.2.1 Software Defined Radio and Software Radio 5 1.2.2 Adaptive Intelligent Software Radio and Other Definitions 8 1.2.3 Functionality, Capability and SBR Evolution 10 1.3 Architectural Perspectives for a Software Based Radio 11 1.3.1 The Radio Implementer plane 11 1.3.2 The Network Operator plane 12 1.4 Software Radio Concepts 13 1.5 Adoption Timeframes for Software Based Radio 15 1.6 Realization of Software Based Radio Requires New Technology 17 1.7 Power/Performance/Price Limitations of Handsets Dictates Inflexible Networks 17 1.8 Regulatory Concepts Facilitate SBR Introduction 18 1.9 Conclusions 20 Acknowledgements 21 References 21 Part II: Front End Technology 23 2 Radio Frequency Translation for Software Defined Radio 25 Mark Beach, Paul Warr & John MacLeod - University of Bristol 2.1 Requirements and Specifications 26 2.1.1 Transmitter Specifications 26 2.1.2 Receiver Specifications 27 2.1.3 Operating Frequency Bands 27 2.2 Receiver Design Considerations 30 2.2.1 Basic Considerations 30 2.2.2 Receiver Architectures 32 2.2.3 Dynamic Range Issues and Calculation 35 2.2.4 Adjacent Channel Power Ratio (ACPR) and Noise Power Ratio (NPR) 41 2.2.5 Receiver Signal Budget 42 2.2.6 Image Rejection 45 2.2.7 Filter Functions within the Receiver 47 2.3 Transmitter Design Considerations 47 2.3.1 Filtering Analogies between Receiver and Transmitter 47 2.3.2 Transmitter Architectures 48 2.3.3 Transmitter Efficiency and Linearity 50 2.4 Candidate Architectures for SDR 56 2.4.1 Zero IF Receivers 56 2.4.2 Quadrature Local Oscillator 59 2.4.3 Variable Preselect Filters 61 2.4.4 Low IF Receivers 66 2.5 Conclusions 70 Acknowledgements 71 References 71 Appendix 73 3 Radio Frequency Front End Implementations for Multimode SDRs 79 Mark Cummings - enVia 3.1 Evolution of Radio Systems 80 3.2 Evolution of RF Front Ends – Superheterodyne Architecture 83 3.3 The AN2/6 Product Family – Dual Band, Six Mode 85 3.3.1 The AN2/6 Architecture 86 3.3.2 Lessons Learned From the AN2/ 6 88 3.4 Alternative RF Front End Architectures 93 3.4.1 Direct Conversion RF Front Ends 93 3.4.2 Pure Digital RF Front Ends 96 3.4.3 Analog Digital Combination Solutions 96 3.4.4 Directions for a Completely Successful SDR RF Front End 97 3.5 Conclusion 98 Acknowledgements 98 References 98 4 Data Conversion in Software Defined Radios 99 Brad Brannon, Chris Cloninger, Dimitrios Efstathiou, Paul Hendriks, Zoran Zvonar – AnalogDevices 4.1 The Importance of Data Converters in Software Defined Radios 99 4.1.1 ADCs for SDR Base Stations 100 4.1.2 ADCs for SDR Handsets 101 4.1.3 DACs for SDR Applications 101 4.2 Converter Architectures 102 4.2.1 Flash Converters 102 4.2.2 Multistage Converters 104 4.2.3 Sigma-Delta Converters 105 4.2.4 Digital-to-Analog Converters 107 4.3 Converter Performance Impact on SDR 109 4.3.1 Noise Sources – Impact on SDR Sensitivity 109 4.3.2 SNR of Data Converter 112 4.3.3 Spurious Impact on Performance 114 4.3.4 Digital-to-Analog Converter Specification 121 4.4 Conclusions and Future Trends 123 References 125 5 Superconductor Microelectronics: A Digital RF Technology for Software Radios 127 Darren K. Brock – HYPRES, Inc. 5.1 Introduction 127 5.1.1 Superconductivity and the Josephson Effect 128 5.1.2 Established Applications of Superconductors 130 5.1.3 Emerging Applications - Software Defined Radio 131 5.2 Rapid Single Flux Quantum Digital Logic 132 5.2.1 Circuit Characteristics 132 5.2.2 Example RSFQ Logic Gate - RS Flip Flop 134 5.2.3 RSFQ Data Converters 135 5.2.4 RSFQ Scaling theory 138 5.3 Cryogenic Aspects 139 5.4 Superconductor SDR for Commercial Applications 140 5.4.1 Superconductors in Wireless Communications 140 5.4.2 Advantages of Superconductor Receivers 141 5.4.3 Trends in Spread Spectrum Communications 143 5.4.4 High Power Amplifier Linearization 145 5.4.5 Digital RF Transceiver 145 5.5 Superconductor SDR for Military Applications 146 5.5.1 Co-Site Interference 146 5.5.2 Digitally Dehopping Spread Spectrum Signals 147 5.5.3 Satellite Communications 148 5.5.4 Accommodating New Waveforms 148 5.5.5 Massive Time Multiplexing 149 5.6 Conclusions 149 Acknowledgements 149 References 150 6 The Digital Front End: Bridge Between RF and Baseband Processing 151 Gerhard Fettweis & Tim Hentschel – Technische Universität Dresden 6.1 Introduction 151 6.1.1 The Front End of a Digital Transceiver 151 6.1.2 Signal Characteristics 153 6.1.3 Implementation Issues 155 6.2 The Digital Front End 155 6.2.1 Functionalities of the Digital Front End 155 6.2.2 The Digital Front End in Mobile Terminals and Base Stations 157 6.3 Digital Up- and Down-Conversion 158 6.3.1 Initial Thoughts 158 6.3.2 Theoretical Aspects 158 6.3.3 Implementation Aspects 161 6.3.4 The CORDIC Algorithm 163 6.3.5 Digital Down-Conversion with the CORDIC Algorithm 165 6.3.6 Digital Down-Conversion by Subsampling 165 6.4 Channel Filtering 167 6.4.1 Low-Pass Filtering after Digital Down-Conversion 167 6.4.2 Band-Pass Filtering before Digital Down-Conversion 172 6.4.3 Filterbank Channelizers 175 6.5 Sample Rate Conversion 181 6.5.1 Resampling after Reconstruction 181 6.5.2 Rational Factor SRC 184 6.5.3 Integer Factor SRC 185 6.5.4 Concepts for SRC 185 6.5.5 Systems for SRC 187 6.6 Example 192 6.6.1 Design Parameters 192 6.6.2 Digital Down-Conversion 193 6.6.3 Sample Rate Conversion 193 6.6.4 Channel Filtering 194 6.6.5 Summary 196 6.7 Conclusion 196 Acknowledgements 197 References 197 Part III: Baseband Technology 199 7 Baseband Processing for SDR 201 David Lund - HW Communications Ltd & Bahram Honary - Lancaster University 7.1 The Role of Baseband Architectures 201 7.2 Software Radio – From Silicon to Software 202 7.3 Baseband Component Technologies 206 7.3.1 Digital Signal Processors 208 7.3.2 Field Programmable Gate Arrays 210 7.3.3 Recent Digital Developments 214 7.3.4 Reconfigurable Analog Components 215 7.3.5 Component Technology Evolution 216 7.4 Design Tools and Methodologies 217 7.4.1 Design Tool Concepts – an Analogy 218 7.4.2 ASIC Design 219 7.4.3 FPGA Design 220 7.4.4 Future Design Flows and Tools 221 7.5 System Design and Maintenance 223 7.5.1 Object Orientation 223 7.5.2 Distributed Resource Management in SDR Processors 224 7.6 Conclusions 230 References and Further Reading 231 8 Parametrization – a Technique for SDR Implementation 233 Friedrich Jondral - University of Karlsruhe 8.1 Definitions 234 8.2 Adaptability 235 8.3 Parametrization of Standards 236 8.3.1 Second Generation – Global System for Mobile Communication (GSM) 236 8.3.2 Second Generation - IS-136 (DAMPS) 238 8.3.3 Third Generation – Universal Mobile Telecommunication System (UMTS) 240 8.4 Parametrization Example 246 8.4.1 A General Modulator 247 8.4.2 Effects of GMSK Linearization 251 8.5 Signal Processing Issues 254 8.5.1 DSP Capabilities and Limitations 254 8.5.2 FPGA Capabilities 255 8.6 Conclusions 255 References 256 9 Adaptive Computing IC Technology for 3G Software-Defined Mobile Devices 257 Paul Master & Bob Plunkett – QuickSilver Technology 9.1 Software Defined Radio – A Solution for Mobile Devices 257 9.1.1 Evolution of Wireless Standards 258 9.1.2 Market Forces Driving SDR for Wireless Devices 260 9.2 The Mobile Application Space and the Need for Processing Power 261 9.2.1 Processing Needs of the 3G Air Interface 261 9.2.2 Processing Needs of Mobile Vocoders 262 9.2.3 Processing Needs of Mobile Video 263 9.3 SDR Baseband Processing – The Implementation Dilemma 265 9.3.1 Limitations of Conventional IC Technologies 266 9.3.2 Resolving the Dilemma 267 9.4 Trade-Offs of Conventional IC Technologies 267 9.4.1 Limitations of Microprocessor and DSP Implementations 268 9.4.2 Limitations of ASIC Implementations 270 9.4.3 Limitations of FPGA Implementations 271 9.5 Hardware with Software Programmability 271 9.5.1 Adaptive Computing Technology 272 9.5.2 The ACM Implementation 273 9.5.3 Design Tools for Adaptive Computing 275 9.6 The Computational Power Efficiency Required by 3G Algorithms 277 9.7 Example Case Studies and Benchmarks 278 9.7.1 CDMA Rake Receiver 278 9.7.2 FIR and IIR Filtering 279 9.7.3 Vocoder 280 9.7.4 Multimedia – MPEG-4 Implementation 284 9.8 Conclusions 286 9.9 Looking to 4G and Beyond 287 References 288 Part IV: Software Technology 289 10 Software Engineering for Software Radios: Experiences at MIT and Vanu, Inc. 291 John Chapin – Vanu, Inc. 10.1 Overview of Vanu Systems 292 10.1.1 Representative Implementations 293 10.1.2 Difference from Other Software Radios 294 10.2 The Importance of Software in Software Radio 295 10.3 Software Portability 295 10.3.1 The Effects of Moore’s Law 296 10.3.2 Exploiting Moore’s Law 297 10.3.3 Generic Data Path 297 10.3.4 Temporal Decoupling 298 10.4 Commodity PC Hardware 300 10.5 Signal Processing Software 300 10.5.1 Data Pull 300 10.5.2 Signal Processing Stages as Objects 301 10.5.3 Stream Abstraction 302 10.5.4 Out of Band Communication 303 10.6 Control Software 303 10.6.1 Code Generation 303 10.6.2 Radio Description Language 304 10.7 Performance 307 10.8 Future Directions 308 Acknowledgements 309 References 309 11 Software Download for Mobile Terminals 311 Paul Bucknell & Steve Pitchers - Philips Research Laboratories 11.1 Why Software Download? 312 11.1.1 Software Reconfiguration 312 11.1.2 Software Downloading Terminals 312 11.1.3 Downloading New Air Interfaces 314 11.2 Downloading Technologies for SDR 314 11.2.1 Granularity 315 11.2.2 Component Communication and Binding 316 11.2.3 Content Function 316 11.2.4 Installation 317 11.2.5 Terminal Wide Aspects 317 11.2.6 Version Management 317 11.3 Standards for Downloading 317 11.3.1 Mobile Standards - 2G/3G Cellular 318 11.3.2 Software Standards 318 11.4 Seamless Upgrading ‘On the Fly’ 320 11.5 Security of Download 321 11.5.1 Secure Downloading of Applications 321 11.5.2 Secure Downloading of Native Software 322 11.6 Software Architectures for Download 323 11.7 Software Download Today - Digital TV 325 11.8 ‘Over the Air’, ‘On the Fly’ Reconfiguration: A Practical Example 326 11.8.1 Architecture 327 11.8.2 Basic Operation 328 11.8.3 Example Reconfigurations 328 11.8.4 Reconfiguration Manager 330 11.8.5 Reconfiguration Procedure 334 11.9 Future Applications of SDR Downloading 336 Acknowledgements 337 References 337 12 Protocols and Network Aspects of SDR 339 Klaus Moessner – Surrey University & Mobile VCE 12.1 Protocol Stacks: SAPs vs Reconfigurability 339 12.1.1 Service Provision via Service Access Points 340 12.1.2 Protocol Configuration and Reconfiguration 341 12.1.3 Interfaces vs SAPs 342 12.2 Approaches to Protocol Stack Reconfiguration 343 12.2.1 Protocols and Protocol Stacks 343 12.2.2 Modular Approaches: Adaptive, Composable & Reconfigurable Protocols 344 12.2.3 Active Networks 349 12.3 Reconfiguration Management And Control 351 12.3.1 The Scope of Reconfiguration Management 352 12.3.2 Requirements of a Management Architecture 354 12.3.3 Management Architecture Implications 357 12.4 Network Support for Software Radios 358 12.4.1 The Network Access and Connectivity Channel 358 12.4.2 The Bootstrap Channel 359 12.4.3 A Global or Universal Control Channel 359 12.4.4 The Interconnected Seamless Network 360 12.5 Conclusions 363 References 363 13 The Waveform Description Language 365 Edward Willink – Thales Research 13.1 The Specification Problem 366 13.2 WDL Overview 367 13.2.1 Decomposition 367 13.2.2 Communication 367 13.2.3 Influences 369 13.2.4 Hierarchical Diagrams 371 13.3 FM3TR Example 374 13.3.1 Protocol Layers 374 13.3.2 Physical Layer Modules 375 13.3.3 Physical Layer Finite State Machine 376 13.3.4 Voice and Data Finite State Machines 377 13.3.5 Hop Modulator 378 13.3.6 Hop Waveform 378 13.3.7 Rise Modulator 379 13.3.8 Summary 381 13.4 Refinement to an Implementation 381 13.4.1 Traditional Development Process 382 13.4.2 Refinement Process 382 13.4.3 Automation 385 13.4.4 The Reference Model 386 13.4.5 Target Environments 387 13.5 WDL Details 388 13.5.1 Type Abstractions 388 13.5.2 Scheduling Abstractions 389 13.5.3 Unified Scheduling Model 391 13.5.4 Leaf Specifications 393 13.6 A Practical WDL Support Environment 394 13.7 Conclusions 396 Acknowledgements 397 References 397 Index 399

About the Author :
Walter Tuttlebee, chief executive of the Virtual Centre of Excellence in Mobile & Personal Communications – Mobile VCE, heads up a unique, not-for-profit company established by the mobile communications industry and academia to undertake long-term, industry-steered, world-class, collaborative research www.mobilevce.com. Mobile VCE's activities include software radio research, an area Walter helped to pioneer in Europe in the mid-1990s, with invited presentations at seminal European conferences organized by the European Commission and the SDR Forum. He has subsequently published and spoken widely in the field. Prior to Mobile VCE Walter led R&D teams in Second and Third generation mobile communications. Aside from his technical interests, Walter previously operated in a business development role and at Mobile VCE he is responsible to the Board for the company's strategy and operations. Walter has also edited books on short range digital wireless, and created on-line industry communities for DECT, Bluetooth and software radio – www.dectweb.org, www.the wirelessdirectory.org, www.softwaredefineradion. He holds an MBA from Cranfield and PhD from Southampton University, is a senior member of the IEEE, a fellow of the IEE and fellow of the RSA.