文件名称：Spread Spectrum and CDMA -- Valery P. Ipatov
文件大小：3.25MB
文件格式：PDF
更新时间：2012-11-03 05:47:32
spreadspectrum CDMA
1 Spread spectrum signals and systems 1 1.1 Basic definition 1 1.2 Historical sketch 5 2 Classical reception problems and signal design 7 2.1 Gaussian channel, general reception problem and optimal decision rules 7 2.2 Binary data transmission (deterministic signals) 11 2.3 M-ary data transmission: deterministic signals 17 2.4 Complex envelope of a bandpass signal 23 2.5 M-ary data transmission: noncoherent signals 26 2.6 Trade-off between orthogonal-coding gain and bandwidth 28 2.7 Examples of orthogonal signal sets 31 2.7.1 Time-shift coding 31 2.7.2 Frequency-shift coding 33 2.7.3 Spread spectrum orthogonal coding 33 2.8 Signal parameter estimation 37 2.8.1 Problem statement and estimation rule 37 2.8.2 Estimation accuracy 39 2.9 Amplitude estimation 41 2.10 Phase estimation 43 2.11 Autocorrelation function and matched filter response 43 2.12 Estimation of the bandpass signal time delay 46 2.12.1 Estimation algorithm 46 2.12.2 Estimation accuracy 48 2.13 Estimation of carrier frequency 53 2.14 Simultaneous estimation of time delay and frequency 55 2.15 Signal resolution 58 2.16 Summary 61 Problems 62 Matlab-based problems 68 3 Merits of spread spectrum 77 3.1 Jamming immunity 77 3.1.1 Narrowband jammer 78 3.1.2 Barrage jammer 80 3.2 Low probability of detection 82 3.3 Signal structure secrecy 87 3.4 Electromagnetic compatibility 88 3.5 Propagation effects in wireless systems 89 3.5.1 Free-space propagation 90 3.5.2 Shadowing 90 3.5.3 Multipath fading 91 3.5.4 Performance analysis 95 3.6 Diversity 98 3.6.1 Combining modes 98 3.6.2 Arranging diversity branches 100 3.7 Multipath diversity and RAKE receiver 102 Problems 106 Matlab-based problems 109 4 Multiuser environment: code division multiple access 115 4.1 Multiuser systems and the multiple access problem 115 4.2 Frequency division multiple access 117 4.3 Time division multiple access 118 4.4 Synchronous code division multiple access 119 4.5 Asynchronous CDMA 121 4.6 Asynchronous CDMA in the cellular networks 124 4.6.1 The resource reuse problem and cellular systems 124 4.6.2 Number of users per cell in asynchronous CDMA 125 Problems 129 Matlab-based problems 130 5 Discrete spread spectrum signals 135 5.1 Spread spectrum modulation 135 5.2 General model and categorization of discrete signals 136 5.3 Correlation functions of APSK signals 137 5.4 Calculating correlation functions of code sequences 139 5.5 Correlation functions of FSK signals 142 5.6 Processing gain of discrete signals 145 Problems 145 Matlab-based problems 146 6 Spread spectrum signals for time measurement, synchronization and time-resolution 149 6.1 Demands on ACF: revisited 149 6.2 Signals with continuous frequency modulation 151 6.3 Criterion of good aperiodic ACF of APSK signals 154 6.4 Optimization of aperiodic PSK signals 155 6.5 Perfect periodic ACF: minimax binary sequences 159 6.6 Initial knowledge on finite fields and linear sequences 161 6.6.1 Definition of a finite field 161 6.6.2 Linear sequences over finite fields 163 6.6.3 m-sequences 165 6.7 Periodic ACF of m-sequences 167 6.8 More about finite fields 170 vi Contents 6.9 Legendre sequences 172 6.10 Binary codes with good aperiodic ACF: revisited 174 6.11 Sequences with perfect periodic ACF 176 6.11.1 Binary non-antipodal sequences 177 6.11.2 Polyphase codes 179 6.11.3 Ternary sequences 181 6.12 Suppression of sidelobes along the delay axis 185 6.12.1 Sidelobe suppression filter 186 6.12.2 SNR loss calculation 187 6.13 FSK signals with optimal aperiodic ACF 192 Problems 194 Matlab-based problems 196 7 Spread spectrum signature ensembles for CDMA applications 203 7.1 Data transmission via spread spectrum 203 7.1.1 Direct sequence spreading: BPSK data modulation and binary signatures 203 7.1.2 DS spreading: general case 207 7.1.3 Frequency hopping spreading 212 7.2 Designing signature ensembles for synchronous DS CDMA 214 7.2.1 Problem formulation 214 7.2.2 Optimizing signature sets in minimum distance 215 7.2.3 Welch-bound sequences 223 7.3 Approaches to designing signature ensembles for asynchronous DS CDMA 227 7.4 Time-offset signatures for asynchronous CDMA 232 7.5 Examples of minimax signature ensembles 235 7.5.1 Frequency-offset binary m-sequences 235 7.5.2 Gold sets 236 7.5.3 Kasami sets and their extensions 239 7.5.4 Kamaletdinov ensembles 241 Problems 243 Matlab-based problems 246 8 DS spread spectrum signal acquisition and tracking 251 8.1 Acquisition and tracking procedures 251 8.2 Serial search 253 8.2.1 Algorithm model 253 8.2.2 Probability of correct acquisition and average number of steps 254 8.2.3 Minimizing average acquisition time 258 8.3 Acquisition acceleration techniques 261 8.3.1 Problem statement 261 8.3.2 Sequential cell examining 262 8.3.3 Serial-parallel search 263 8.3.4 Rapid acquisition sequences 264 8.4 Code tracking 265 8.4.1 Delay estimation by tracking 265 8.4.2 Early–late DLL discriminators 267 8.4.3 DLL noise performance 270 Problems 273 Matlab-based problems 274 Contents vii 9 Channel coding in spread spectrum systems 277 9.1 Preliminary notes and terminology 277 9.2 Error-detecting block codes 279 9.2.1 Binary block codes and detection capability 279 9.2.2 Linear codes and their polynomial representation 281 9.2.3 Syndrome calculation and error detection 284 9.2.4 Choice of generator polynomials for CRC 285 9.3 Convolutional codes 286 9.3.1 Convolutional encoder 286 9.3.2 Trellis diagram, free distance and asymptotic coding gain 289 9.3.3 The Viterbi decoding algorithm 292 9.3.4 Applications 296 9.4 Turbo codes 296 9.4.1 Turbo encoders 296 9.4.2 Iterative decoding 299 9.4.3 Performance 300 9.4.4 Applications 301 9.5 Channel interleaving 302 Problems 302 Matlab-based problems 304 10 Some advancements in spread spectrum systems development 307 10.1 Multiuser reception and suppressing MAI 307 10.1.1 Optimal (ML) multiuser rule for synchronous CDMA 307 10.1.2 Decorrelating algorithm 309 10.1.3 Minimum mean-square error detection 311 10.1.4 Blind MMSE detector 314 10.1.5 Interference cancellation 315 10.1.6 Asynchronous multiuser detectors 316 10.2 Multicarrier modulation and OFDM 316 10.2.1 Multicarrier DS CDMA 317 10.2.2 Conventional MC transmission and OFDM 318 10.2.3 Multicarrier CDMA 322 10.2.4 Applications 325 10.3 Transmit diversity and space–time coding in CDMA systems 326 10.3.1 Transmit diversity and the space–time coding problem 326 10.3.2 Efficiency of transmit diversity 327 10.3.3 Time-switched space–time code 329 10.3.4 Alamouti space–time code 331 10.3.5 Transmit diversity in spread spectrum applications 333 Problems 334 Matlab-based problems 336 11 Examples of operational wireless spread spectrum systems 339 11.1 Preliminary remarks 339 11.2 Global positioning system 339 11.2.1 General system principles and architecture 340 11.2.2 GPS ranging signals 341 11.2.3 Signal processing 343 viii Contents 11.2.4 Accuracy 344 11.2.5 GLONASS and GNSS 344 11.2.6 Applications 345 11.3 Air interfaces cdmaOne (IS-95) and cdma2000 345 11.3.1 Introductory remarks 345 11.3.2 Spreading codes of IS-95 346 11.3.3 Forward link channels of IS-95 347 11.3.3.1 Pilot channel 347 11.3.3.2 Synchronization channel 347 11.3.3.3 Paging channels 348 11.3.3.4 Traffic channels 349 11.3.3.5 Forward link modulation 351 11.3.3.6 MS processing of forward link signal 352 11.3.4 Reverse link of IS-95 353 11.3.4.1 Reverse link traffic channel 353 11.3.4.2 Access channel 355 11.3.4.3 Reverse link modulation 355 11.3.5 Evolution of air interface cdmaOne to cdma2000 356 11.4 Air interface UMTS 357 11.4.1 Preliminaries 357 11.4.2 Types of UMTS channels 358 11.4.3 Dedicated physical uplink channels 359 11.4.4 Common physical uplink channels 360 11.4.5 Uplink channelization codes 361 11.4.6 Uplink scrambling 362 11.4.7 Mapping downlink transport channels to physical channels 363 11.4.8 Downlink physical channels format 364 11.4.9 Downlink channelization codes 365 11.4.10 Downlink scrambling codes 365 11.4.11 Synchronization channel 366 11.4.11.1 General structure 366 11.4.11.2 Primary synchronization code 366 11.4.11.3 Secondary synchronization code 367 References 369 Index 375