WIRELESS TRANSCEIVER ARCHITECTURE BRIDGING RF AND DIGITAL COMMUNICATIONS Pierre Baudin Wiley
Contents Preface List of Abbreviations Nomenclature xiii xvii xxi Part I BETWEEN MAXWELL AND SHANNON 1 The Digital Communications Point of View 3 1.1 Bandpass Signal Representation 4 1.1.1 RF Signal Complex Modulation 4 1.1.2 Complex Envelope Concept 8 1.1.3 Bandpass Signals vs. Complex Envelopes 13 1.2 Bandpass Noise Representation 32 1.2.1 Gaussian Components 34 1.2.2 Phase Noise vs. Amplitude Noise 38 1.3 Digital Modulation Examples 44 1.3.1 Constant Envelope 44 1.3.2 Complex Modulation 50 1.3.3 Wideband Modulation 56 1.4 First Transceiver Architecture 66 1.4.1 Transmit Side 67 1.4.2 Receive Side 69 2 The Electromagnetism Point of View 73 2.1 Free Space Radiation 73 2.1.1 Radiated Monochromatic Far-field 74 2.1.2 Narrowband Modulated Fields 81 2.1.3 Radiated Power 89 2.1.4 Free Space Path Loss 94 2.2 Guided Propagation 98 2.2.1 Transmission Lines 98 2.2.2 Amplitude Matching 105 2.2.3 Power Matching 107
viii Contents 2.3 The Propagation Channel 115 2.3.1 Static Behavior 116 2.3.2 Dynamic Behavior 126 2.3.3 Impact on Receivers 134 3 The Wireless Standards Point of View 145 3.1 Medium Access Strategies 145 3.1.1 Multiplexing Users 145 3.1.2 Multiplexing Uplink and Downlink 146 3.1.3 Impact on Transceivers 149 3.2 Metrics for Transmitters 151 3.2.1 Respect for the Wireless Environment 152 3.2.2 Transmitted Signal Modulation Quality 161 3.3 Metrics for Receivers 167 3.3.1 Resistance to the Wireless Environment 167 3.3.2 Received Signal Modulation Quality 174 Part II IMPLEMENTATION LIMITATIONS 4 Noise 183 4.1 Analog Electronic Noise 184 4.1.1 Considerations on Analog Electronic Noise 184 4.1.2 Thermal Noise 184 4.2 Characterization of Noisy Devices 186 4.2.1 Noise Temperatures 186 4.2.2 Noise Factor 191 4.2.3 Noise Voltage and Current Sources 199 4.2.4 Cascade ofnoisy Devices 210 4.2.5 Illustration 214 4.2.6 SNR Degradation 229 4.3 LO Phase Noise 231 4.3.1 RF Synthesizers 232 4.3.2 Square LO Waveform for Chopper-like Mixers 243 4.3.3 System Impact 252 4.4 Linear Error Vector Magnitude 263 4.5 Quantization Noise 266 4.5.1 Quantization Error as a Noise 267 4.5.2 Sampling Effect on Quantization Noise 278 4.5.3 Illustration 282 4.6 Conversion Between Analog and Digital Worlds 287 4.6.1 Analog to Digital Conversion 287 4.6.2 Digital to Analog Conversion 302
Contents 5 Nonlinearity 307 5.1 Smooth AM-AM Conversion 308 5.1.1 Smooth AM-AM Conversion Model 308 5.1.2 Phase/Frequency Only Modulated RF Signals 313 5.1.3 Complex Modulated RF Signals 339 5.1.4 SNR Improvement Due to RF Compression 317 5.2 Hard AM-AM Conversion 392 5.2.1 Hard Limiter Model 393 5.2.2 Hard Limiter Intercept Points 394 5.2.3 SNR Improvement in the Hard Limiter 398 5.3 AM-PM Conversion and the Memory Effect 402 5.3.1 Device Model 402 5.3.2 System Impacts 407 5.4 Baseband Devices 413 6 RF Impairments 417 6.1 Frequency Conversion 417 6.1.1 From Complex to Real Frequency Conversions 417 6.1.2 Image Signal All 6.1.3 Reconsidering the Complex Frequency Conversion 423 6.1.4 Complex Signal Processing Approach 426 6.2 Gain and Phase Imbalance 437 6.2.1 Image Rejection Limitation 437 6.2.2 Signal Degradation 442 6.3 Mixer Implementation 453 6.3.1 Mixers as Choppers 453 6.3.2 Impairments in the LO Generation 455 6.4 Frequency Planning 482 6.4.1 Impact of the LO Spectral Content 483 6.4.2 Clock Spurs 487 6.5 DC Offset and LO Leakage 489 6.5.1 LO Leakage on the Transmit Side 490 6.5.2 DC Offset on the Receive Side 492 Part III TRANSCEIVER DIMENSIONING 7 Transceiver Budgets 497 7.1 Architecture of a Simple Transceiver 497 7.2 Budg eting a Transmitter 499 7.2.1 Review of the ZIF TX Problem 499 7.2.2 Level Diagrams and Transmitter High Level Parameters 505 7.2.3 Budgets Linked to Respectfor the Wireless Environment 511 7.2.4 Budgets Linked to the Modulation Quality 524 7.2.5 Conclusion 531
X Contents 7.3 Budgeting a Receiver 532 7.3.1 Review of the ZIF RX Problem 532 7.3.2 Level Diagrams and Receiver High Level Parameters 539 7.3.3 Budgets Linked to the Resistance to the Wireless Environment 554 7.3.4 Budgets Linked to the Modulation Quality 566 7.3.5 Conclusion 580 8 Transceiver Architectures 583 8.1 Transmitters 583 8.7.7 Direct Conversion Transmitter 584 8.1.2 Heterodyne Transmitter 588 8.1.3 Variable-IF Transmitter 592 8.1.4 Real-IF Transmitter 594 8.1.5 PLL Modulator 596 8.1.6 Polar Transmitter 602 8.7.7 Transmitter Architectures for Power Efficiency 612 8.2 Receivers 629 8.2.7 Direct Conversion Receiver 629 8.2.2 Heterodyne Receiver 632 8.2.3 Low-IF Receiver 635 8.2.4 PLL Demodulator 639 9 Algorithms for Transceivers 643 9.1 Transmit Side 643 9.1.1 Power Control 644 9.7.2 LO Leakage Cancellation 650 9.1.3 P/Q Imbalance Compensation 654 9.1.4 Predistortion 661 9.7.5 Automatic Frequency Correction 669 9.7.6 Cartesian to Polar Conversion 672 9.2 Receive Side 675 9.2.7 Automatic Gain Control 675 9.2.2 DC Offset Cancellation 680 9.2.3 P/Q Imbalance Compensation 683 9.2.4 Linearization Techniques 689 9.2.5 Automatic Frequency Correction 691 APPENDICES Appendix 1 Correlation 697 A 1.1 Bandpass Signals Correlations 697 A 1.2 Properties of Cross-Correlation Functions 703 A 1.3 Properties of Autocorrelation Functions 704
Contents, xi Appendix 2 Stationarity 707 A2.1 Stationary Bandpass Signals 707 A2.2 Stationary Complex Envelopes 710 A2.3 Gaussian Case 711 Appendix 3 Moments of Normal Random Vectors 713 A3.1 Real Normal Random Vectors 713 A3.2 Complex Normal Random Vectors 716 References 719 Index 723