Practical Digital Wireless Signals -...

Practical Digital Wireless Signals

Do you need to know what signal type to select for a wireless application? Quicklydevelop a useful expertise in digital modulation with this practical guide, based on theauthor’s industry experience of more than 30 years. You will understand the physicalmeaning behind the mathematics of wireless signals and learn the intricacies and trade-offs in signal selection and design.

Key features:� Six modulation families and 12 modulation types are covered in depth

� A quantitative ranking of relative cost incurred to implement any of 12 differentmodulation types

� Extensive discussions of the Shannon Limit, Nyquist filtering, efficiency measures,and signal-to-noise measures

� Radio wave propagation and antennas, multiple access techniques, and signal codingprinciples are all covered

� Spread spectrum and wireless system operation requirements are presented.

Earl McCune is a practicing engineer and Silicon Valley entrepreneur. A graduate of UCBerkeley, Stanford University, and UC Davis, he has over 30 years of post-graduateindustry experience in wireless communications circuits and systems. Now semi-retired,he has founded two successful start-up companies, each of them winning industrialawards for their technical innovation.

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Cambridge University Press978-0-521-51630-3 - Practical Digital Wireless SignalsEarl McCuneFrontmatterMore information

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the cambridge rf and microwave engineering series

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Steve C. Cripps, Visiting Professor, Cardiff University

Peter Aaen, Jaime A. Pla and John Wood, Modeling and Characterization of RF and MicrowavePower FETs

Dominique Schreurs, Máirtín O’Droma, Anthony A. Goacher and Michael Gadringer,RF Power Amplifier Behavioral Modeling

Fan Yang and Yahya Rahmat-Samii, Electromagnetic Band Gap Structures in AntennaEngineering

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Forthcoming

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Patrick Roblin, Nonlinear RF Circuits and the Large-Signal Network Analyzer

David E. Root, Jason Horn and Jan Verspecht, X-Parameters

Dominique Schreurs, Microwave Techniques for Microelectronics

Sorin Voinigescu, High-Frequency Integrated Circuits

John L. B. Walker, Handbook of RF and Microwave Solid-State Power Amplifiers

John Wood, Peter Aaen and Mohamed Sayed, Modern RF and Microwave MeasurementTechniques






Practical Digital Wireless Signals

EARL McCUNE






cambr idge univers ity pres s

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Cambridge University PressThe Edinburgh Building, Cambridge CB2 8RU, UK

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Dedicated to the memory of my father

Earl McCune Sr.

for instilling in me the great value of intuitive understanding of

technical fundamentals






Contents

Preface page xviiDefinitions and acronyms xxTerminology and notation xxv

1 Keying, states, and block diagram construction 1

1.1 Radio communications: what really happens? 21.2 Modulation states: “keyed” 31.3 DWC signal representations 6

1.3.1 “Digital” modulations of an analog signal 61.3.2 Polar representation 61.3.3 Quadrature representation 71.3.4 Transformations between signal representations 9

1.4 Frequency domain representations 111.5 Implementing a DWC system 13

1.5.1 Symbol construction 131.5.2 Symbol-to-signal-state mapping 141.5.3 State transitions 151.5.4 Modulator 171.5.5 Power amplifier (PA) 171.5.6 Radio front-end 18

Simplex 18Duplex 19Duplexer vs. diplexer 20

References 22For further reading 22

2 Common issues and signal characterization 23

2.1 Power spectral density (PSD) 232.2 Occupied bandwidth 28

2.2.1 Useful signal-bandwidth measures 29Bounded power-spectral-density (B-PSD) bandwidth 29Fractional power-containment bandwidth 31Transmitter mask 33






2.2.2 Bad signal-bandwidth measures 33Null-to-null bandwidth 33Equivalent white-noise signal bandwidth (ENSB) 34

2.3 Bandlimiting filtering 352.3.1 Exact vs. good enough 372.3.2 Filtering pulses 37

Full response 38Partial response 38

2.3.3 Superposition 382.3.4 Intersymbol interference (ISI) 402.3.5 Nyquist filters 402.3.6 Matched filtering 43

2.4 Informational diagrams 472.4.1 Constellation diagram 472.4.2 Vector diagram 482.4.3 “Eye” diagram 48

2.5 Interference and near-far interference (NFI) 502.6 Signals and noise 52

2.6.1 Signal-to-noise ratio (SNR) 532.6.2 Carrier-to-noise ratio (CNR) 532.6.3 Information bit-energy-to-noise-density (IBEND) Eb/N0 53

2.7 Channel (Shannon) capacity 562.8 Important DWC signal measures 58

2.8.1 Efficiency measures 58Bandwidth efficiency 58Energy (DC) efficiency 59Output efficiency 61Peak efficiency 61Backoff efficiency 61Supply-referenced efficiency 62Power-added efficiency 63Overall transmitter efficiency 63Power efficiency 63

2.8.2 Error vector 652.8.3 Off-channel power ratio 662.8.4 Envelope dynamics 67

Signal power 67Peak-to-average power ratio (PAPR) 67PDF/CDF/CCDF curves 68

2.9 Circuitry impacts from the signal selection 70Constant-envelope (CE) signals 71Envelope-varying (EV) signals 71Output-power control 72

viii Contents






Duplex method 72Slew rate 72


3 Important details on results from Shannon, Nyquist, and others 74

3.1 DWC channel capacity – the fundamental work of Claude Shannon 743.1.1 Basic capacity relationships to SNR 753.1.2 Basic capacity relationships to IBEND 783.1.3 Finite available power 813.1.4 Power vs. bandwidth for a set capacity 813.1.5 Signal design region: adaptive modulation 83

3.2 Equivalent noise bandwidth (ENB) 853.2.1 ENB of filters 863.2.2 Limitations of the ENB concept 87

3.3 Digital bandlimiting filtering 883.3.1 Conventional digital filtering 88

Finite-impulse-response (FIR) filters 88Infinite-impulse-response (IIR) filters 88

3.3.2 Generalized Nyquist filter construction (GNFC) 893.3.3 The DZ (derivative-zeroed) pulse family 953.3.4 Superposition lowpass filtering (SLPF) 98


4 Digital amplitude modulation (ASK) 102

4.1 Signals and characteristics 1024.1.1 Amplitude shift keying definition 1024.1.2 Modulation index and envelope dynamic range 103

Important special case: on-off keying (OOK) 1044.1.3 ASK constellation diagrams 1044.1.4 Spectrum and signal bandwidth 1044.1.5 ASK bandwidth efficiency 1064.1.6 ASK power efficiency 1074.1.7 PAPR characteristics 1084.1.8 Additive noise 109

4.2 ASK signal generation 1114.2.1 Variable gain amplifier (VGA) 1114.2.2 PA DC-power modulation 1124.2.3 Complete-power keying for OOK 1134.2.4 Transmitter energy efficiency characteristics 114

4.3 ASK signal demodulation principles 1144.3.1 Diode 118

Contents ix






4.3.2 Demodulating logamp/received-signal-strength indication (RSSI) 1194.3.3 Automatic gain control (AGC) 1204.3.4 Coherent 121


5 Digital frequency modulation: FSK 124

5.1 Signals and characteristics 1245.1.1 Frequency shift keying definition 1245.1.2 Modulation index 127

Important special case: minimum shift keying (MSK) 1305.1.3 Spectrum and signal bandwidth 131

Important special cases: Gaussian-filtered FSK 1365.1.4 FSK bandwidth efficiency 1385.1.5 FSK power efficiency 1405.1.6 Doppler shift 1405.1.7 Additive noise 142

Threshold effect 142Clicks and doublets 143

5.2 FSK signal generation 1455.2.1 Switched oscillators 1455.2.2 Voltage-controlled oscillator (VCO) 1465.2.3 Fractional-division loop 1475.2.4 Two-point modulation 1485.2.5 Opened-loop modulation 1495.2.6 Direct digital (frequency) synthesis (DDS, or also DDFS) 1505.2.7 Transmitter energy-efficiency characteristics 151

5.3 FSK signal demodulation principles 1515.3.1 Limiters: compression and capture effects 1525.3.2 Slope demodulation 1555.3.3 Frequency discriminators 155

Resonator 156Delay line 156Pulse density 157

5.3.4 D-flipflop (DFF) 1575.3.5 Phaselock loop (PLL) 158


6 Digital phase modulation: PSK 160

6.1 Signals and characteristics 160Author’s dilemma 160

6.1.1 Phase shift keying 160

x Contents






6.1.2 Vector diagrams 163CDF examples for linear transitions 165

6.1.3 PSK phase diagram 1666.1.4 Delay equivalence 1676.1.5 Offset modulation (O-PSK) 1676.1.6 Rotated modulation 1696.1.7 Spectrum and signal bandwidth 1706.1.8 Bandwidth efficiency 1746.1.9 Power efficiency 1756.1.10 Doppler effects 1756.1.11 Additive noise 177

Author’s dilemma reprise 1786.2 PSK signal generation 178

6.2.1 Quadrature modulation 1796.2.2 Mixer (BPSK) 1796.2.3 Delay 1806.2.4 Direct digital synthesis (DDS) 180

6.3 PSK signal demodulation principles 1806.3.1 Quadrature demodulation 1816.3.2 Differential demodulation 1826.3.3 Direct phase demodulation 183


7 Combined digital modulations: QAM and OFDM 185

7.1 Signal types and characteristics 1857.2 Quadrature amplitude modulation (QAM) 185

7.2.1 Constellation diagrams 1867.2.2 Spectrum and signal bandwidth 1897.2.3 Bandwidth efficiency 1907.2.4 Power efficiency 1907.2.5 PAPR characteristics 1927.2.6 Offset QAM 1937.2.7 Doppler sensitivity 1937.2.8 Additive noise performance 1957.2.9 Demodulation principles for QAM 2027.2.10 Tradeoff summary 2037.2.11 Signal generation and demodulation 204

Essentially always quadrature 204Using DDS to generate QAM 204

7.3 Orthogonal frequency division modulation (OFDM) 204Why does OFDM exist? 204

Contents xi






Basic OFDM principles 206Signal order of OFDM 208

7.3.1 OFDM fundamentals 2087.3.2 Waveform discontinuity 2107.3.3 Cyclic prefix 2117.3.4 OFDM constellation diagrams 2127.3.5 Spectrum and signal bandwidth 2137.3.6 Bandwidth efficiency 2147.3.7 PAPR characteristics 2167.3.8 Energy efficiency 2187.3.9 Doppler sensitivity 2197.3.10 Signal generation and demodulation 220

Important special case: 3G long-term evolution (LTE) 2217.3.11 Demodulation principles for OFDM 2237.3.12 Tradeoff summary 224


8 Spread spectrum 226

8.1 General principles and characteristics 2268.1.1 Cyclic cancellation 2288.1.2 Synchronization 2288.1.3 Interference suppression 2318.1.4 Process gain 2328.1.5 Jamming margin 2338.1.6 Spreading codes, and chips 234

8.2 Frequency-hopping spread spectrum 2358.2.1 Basic operation 2358.2.2 Synchronization 2378.2.3 Slow and fast frequency hopping 2388.2.4 Modulation selection 2388.2.5 Process gain 2398.2.6 Interference suppression 2398.2.7 Jamming margin 240

8.3 Direct-sequence spread spectrum 2408.3.1 Basic operation 240

Negative input SNR 2418.3.2 Synchronization 2428.3.3 De-spreader location 2438.3.4 Modulation selection 2448.3.5 Process gain 2448.3.6 Interference suppression 2458.3.7 Jamming margin 245

xii Contents






8.4 Summary 246References 246For further reading 247

9 Wireless propagation and antenna fundamentals 248

9.1 Free-space propagation 2499.2 Antenna properties 250

9.2.1 Antenna gain 2519.2.2 Directivity 2539.2.3 Near and far fields 2549.2.4 Polarization 255

9.3 Path loss 2569.4 Optical equivalence of propagation 258

9.4.1 Reflections 2599.4.2 Shadowing, diffraction, and refraction 2619.4.3 Polarization 262

9.5 Doppler shifts 2629.6 Fading 262

Block errors and fade margin 2639.7 Diversity 264

Spatial diversity 265Polarization diversity 265Frequency diversity 266Diversity summary 266

9.8 Level diagrams 266GEO satellite system example 267Personal-area communication example 268

9.9 Specific absorption ratio (SAR) 269References 269For further reading 269

10 Principles of coding 270

10.1 Why do coding? And what is coding anyway? 27010.2 Basic principles of coding 27110.3 Coding for bandwidth efficiency 27310.4 Coding for spectrum control and link operation 27410.5 Coding for error control 277

10.5.1 Approaching the Shannon Limit 27710.5.2 New tradeoffs 28010.5.3 Block coding 281

Block coding for error detection 281Block coding for error correction 282

Contents xiii






10.5.4 Convolutional coding 28410.5.5 Interleaving: coding for burst errors 28710.5.6 Iteratively decoded coding (e.g. Turbo, LDPC) 28910.5.7 Combination coding: inner and outer codes 29010.5.8 Trellis coded modulation (TCM) 292

Trellis diagrams 292Bandwidth efficiency 295

10.6 Coding for channel throughput 29510.7 Equalization 296References 297For further reading 297

11 Multiple access techniques 299

11.1 Carrier sense (CSMA) 29911.1.1 Protocol basics 30011.1.2 Hidden node problem 300

11.2 Frequency division (FDMA) 30111.2.1 Channel designations 30211.2.2 Coverage strategies 30311.2.3 Protocol basics 304

Duplexing 30411.3 Time division (TDMA) 305

11.3.1 Framing 30511.3.2 Burst ramp-up and ramp-down spectral effects 307

11.4 Code division (CDMA) 30811.4.1 Signal separation 30811.4.2 Multiple access interference (MAI) 31011.4.3 Power control is essential 31111.4.4 Logical channels: “code space” 314

11.5 Orthogonal FDMA 31411.5.1 Subcarrier assignment 31511.5.2 Orthogonality in the uplink 315

11.6 Space division (SDMA) 316References 318For further reading 319

12 Signal tradeoffs and system evolution 320

12.1 Receiver implications of modulation choice 32212.2 Signal-bandwidth efficiency comparison 32712.3 Power amplifier cost issues 33012.4 Signal tolerance of channel-induced problems 33112.5 Keep-it-Simple ranking of DWC signals 332

xiv Contents






12.6 Existing systems and their modulation selections 335Long, long ago in a place not very far away … 336


Tutorial AppendicesAppendix A: Phasor review 341Appendix B: Decibels (dB) really are simple 343Appendix C: Analog modulation basics 347Appendix D: Quadrature modulation and demodulation principles 359Appendix E: Polar modulation and demodulation principles 372Appendix F: The derivative-zeroed pulse family 379Appendix G: Selected DWC standards and their modulations 389

Remote Control Zigbee, RKE, TPMSCordless Telephone CT, PHS, DECTCellular Analog (historical), NADC, PDC, GSM/GPRS,

EDGE, Wideband-CDMA, HSDPA, HSUPA, LTE,cdmaOne (IS-95), cdma2000 1×RTT, EV-DO

Public Service Analog (historical), APCO-25, TETRAWireless Data 802.11 (DS and FH), Wi-Fi 1 (802.11b), Wi-Fi 2

(802.11a/g), WiMAX (fixed), WiMAX (mobile)Personal Area Bluetooth 1.0, Bluetooth – EDR 2.0, Bluetooth –

EDR 2.1Index 401

Contents xv






Preface

Wireless communications is rapidly becoming one of the ubiquitous technologicalunderpinnings of modern society (such as electric power, fossil fuels, automobiles,etc.). Few people think about the technology within their mobile phones, remote controls,garage door openers, GPS navigation devices, and so on. These devices are always athand and reliably work for the user.

Yet even within the electrical engineering (EE) community, radio communicationtechniques have a reputation as a “Black Art” that can only be successfully practicedby “RF people”. This is changing, albeit slowly. Any significant progress in successfullyopening this vital technology widely to more practitioners must remove this “Black Art”stigma. In my opinion this is best achieved through outreach from existing successful“RF people”. This outreach must occur through many channels, such as this book andnew courses in both academic and industrial training.

Today it takes many years to train communications engineers in the intricacies ofwireless signal modulation tradeoffs. I am a product of this decades-long process. Muchof this difficulty, for me anyway, is a consequence of the mathematical approach taken toall modulation training. The objective of this book is to begin to add a comprehensive yetphysical approach alongside this traditional modulation training.

The contents of this book are drawn from the nearly 40 years of experience I have withradio communication technology. Being much more of a physics-based person instead ofa mathematician, to build my own understanding of this material over these decades Ihave put in a lot of effort to get through the mathematics and into also understanding theunderlying physical relationships. Through these pages I can share my results with you.

One major premise of this book comes from advice I received from my father as Ibegan learning electronics: “Don’t memorize equations to learn the material. Instead,carefully learn the fundamental principles. Then as you need an equation, if it is notmemorized it can be quickly derived on the spot.” He lived by this rule, and it hasdefinitely served me very well over the years. And now in the age where computers domuch of the math anyway, it is vital to be able to check any computer output forreasonableness. A surprising output may be the result of a programming error whichcan be quickly fixed to avoid embarrassment. Then again, it may be a clue to a significanttechnology contribution. The difference can only be known if fundamental physicalprinciples are well understood.

The presentation order within this book is carefully planned so that material needed tounderstand the topic at hand has been presented previously as much as possible. Cross






references to important sections are included to facilitate connections to supportingmaterial.

In this approach, mathematics is a tool for later illustration instead of the primarywindow through which to view and learn the material. Certainly, for those readers whowish to delve more deeply into the theory of any topic, a suggested list for further readinginto the excellent theoretic literature is provided at the end of each chapter.

Unique contributions in this book include:

� Detailed discussion on the consequences of the Shannon capacity, showing how thislimit impacts bandwidth efficiency, transmitter power, and signal design.

� Introduction of a channel utilization factor U in Shannon’s capacity equation, showinghow system performance is affected when operation at the theoretical capacity is notattempted.

� A completely non-mathematical presentation on principles of coding for improvedbandwidth efficiency (compression), for error control, and for spectral shaping andlink control. This presentation includes examples of how the error correction processworks when decoding convolutional codes.

� Clarification of the difference between signal-to-noise ratio and IBEND (also calledEb/N0).� Clarification of the difference between power efficiency and energy efficiency.� Quantification of six different measures of energy efficiency.� Details on the Generalized Nyquist Filter Construction (GNFC) technique, showingthat the widely used spectral raised-cosine filter can be greatly improved.

� Resolution of the perceived ambiguity between “diplexer” and “duplexer” – these arevery different.

� Introduction of a family of “maximally smooth” pulses/windows at their endpoints: theDerivative Zeroed pulses.

� Using the superposition lowpass filter (SLPF) to greatly reduce transmitter hardwareand also eliminate the x/sinx corrector for conventional Nyquist filtering.

� Demodulation principles, listed separately for all modulation types.� Complete description for FSK modulation index h for two normalizations: fixedfrequency spacing, and fixed total deviation.

� Modified Carson’s Rule for estimating the bandwidth of FSK signals “60 dB down”.

� The first physical explanation I have ever seen for the FM threshold effect.� Clarification of the difference between pure PSK, a constant envelope signal, andconventional PSK which really is a special case of QAM.

� Clarification that CPM is really a FSK, and is not a PSK.� Presentation of OFDM-signal principles without using the inverse Fourier Transform –

why the Fourier transform technique works for OFDM is derived later.� Explanation of why, physically, matched filters work so well.

� Introduction of the Keep-it-Simple (KIS) technique of signal modulation selection.� Quantified comparison among 12 digital modulation types to illustrate their relativecosts of implementation.

This book is aimed at practitioners in industry who may be new to digital communica-tions via radio. It assumes a basic familiarity with radio concepts, so it is not a tutorial in

xviii Preface






general radio technology. This book can be used as a supplementary reference foruniversity and graduate study. Any architect of communications features in productswill find this very useful – particularly if they are new to digital radio.

Basic familiarity with analog modulation for AM, FM, and PM is covered in tutorialAppendix C, to provide an internal reference to the important topics drawn from fordigital modulations.

A completely non-mathematical discussion of signal and information coding is inChapter 10. This chapter was a challenge because while coding is widely used and ofvital importance to modern digital communications, its successful implementationrequires intensive mathematical understanding. Yet to understand what coding is andwhy it works it is not necessary to use mathematics at all. For those needing to get intoimplementation details of coding a bibliography is presented for further study at the endof Chapter 10.

Saving the best for last, I wish to particularly acknowledge the tremendous help ofDr. DietmarWenzel in editing this manuscript, and to Professors Khaled Abdel-Ghaffar andZhi Ding from the University of California Davis in helping work out the non-mathematicaltreatment of coding principles. Dr. Floyd M. Gardner remains a long-time inspiration and aparticular guide for the ideas of Section 3.1 on consequences fromShannon’s limit. The helpof David Huynh, Dave Jackson, and Javier Castelblanco from Agilent Technologies inmaking the many measurements in Appendix G made that part possible.

Special thanks go to series editor Steve Cripps, who made it very clear to me that thisbook should be written NOW.

And the tolerance of my wife Barbara to the seemingly endless hours spent writing,drawing, rewriting, and editing needed for the preparation of this book is beyondmeasure. My gratitude to you is boundless!

I fervently hope that all who read this book, and who may use it as an additionalreference, will enjoy this approach as much as I have enjoyed writing it.

Earl McCune

Preface xix






Definitions and acronyms

Term Definition

Filter a signal processing operation where the domain of the input andoutput signals is unchanged

Transform a signal processing operation where the domain of the input andoutput signals is changed

Signal Circle the circle of unit radius in the I-Q plane, containing all possibleconstellation points

Acronym Meaning

ACK acknowledgementACP adjacent-channel powerACPR adjacent-channel power ratioADC analog-to-digital converterAGC automatic gain controlAltCP alternate channel powerAM amplitude modulationARQ automatic repeat requestASK amplitude-shift keyingBASK binary amplitude-shift keyingBER bit error rateBFSK binary frequency-shift keyingBH3 Blackman–Harris 3-term pulse (window)bps bits per secondB-PSD bounded power spectral densityBPSK binary phase-shift keyingBW bandwidthCCC cubic congruence codesCCDF complementary cumulative density functionCCK complementary code keyingCDF cumulative distribution functionCDM code-division multiplexingCDMA code-division multiple accessCE constant envelope






CMOS complementary metal-oxide-semiconductorCNR carrier-to-noise ratioCORDIC coordinated-rotation digital computer (algorithm)cp cyclic prefixCP continuous phaseCPFSK continuous-phase frequency-shift keyingCPM continuous-phase modulationcPSK conventional PSKCRC cyclic redundancy checkCSMA carrier-sense multiple accessCTS clear to sendDAC digital-to-analog converterdB decibeldBc decibels relative to carrier (total signal) powerDC direct currentDDFS direct digital frequency synthesisDDS direct digital synthesizerDFF D type flip-flopDFT discrete Fourier TransformDLL delay-locked loopDMT discrete multi-toneD-PSK differential phase-shift keyingDS direct sequenceDSB double sidebandDSP digital signal processingDSSS direct-sequence spread spectrumDWC digital wireless communicationDZEn derivative-zeroed even pulse (window) of order nDZn derivative-zeroed pulse (window) of order nEC error correctionECC error-correction codeED error detectionEDGE enhanced data rates for GSM evolutionEDR envelope dynamic rangeEIRP effective isotropic radiated powerEM electromagneticENB equivalent noise bandwidthENSB equivalent noise signal bandwidthEV envelope varyingEVM error-vector magnitudeEVP error-vector phaseFD full-duplexFDM frequency division multiplexing

Definitions and acronyms xxi






FDMA frequency division multiple accessFEC forward error correctionFET field effect transistorFFH fast frequency hoppingFFT fast Fourier TransformFH frequency hoppingFHSS frequency-hopping spread spectrumFIBP fractional in-band powerFIR finite impulse responseFLL frequency-lock loopFM frequency modulationFOOB fractional out-of-band powerFR full responseFSK frequency-shift keyingFUR Fourier uncertainty relationGFSK Gaussian-filtered frequency-shift keyingGHz gigahertz (billion cycles per second)GLPF Gaussian lowpass filterGMSK Gaussian-filtered minimum shift keyingGNFC generalized Nyquist filter constructionGPRS general packet radio serviceGSM global system of mobile communicationHD half-duplexI in-phase axis; in-phase signal componentIBEND Information-Bit-Energy-to-Noise Density ratioIEEE Institute of Electrical and Electronic Engineers ™IIR infinite impulse responseISI inter-symbol interferenceISR interference-to-signal ratiokHz kilohertz (thousand cycles per second)KIS keep-it-simpleLFSR linear feedback shift registerLO local oscillatorLOS line of sightLPF lowpass filterLTE long-term evolution of the third generation cellular networkM signal order, number of available signal statesMA multiple accessMAI multiple access interferenceM-ASK M-ary amplitude-shift keyingM-FSK M-ary frequency-shift keyingMHz megahertz (million cycles per second)MIMO multiple-input multiple-output

xxii Definitions and acronyms






M-PSK M-ary phase-shift keyingMSK minimum-shift keyingNACK not acknowledgedNBFM narrowband frequency modulationNBPM narrowband phase modulationNFI near-far interferenceNLOS non line of sightOB occupied bandwidthOBO output backoffOFDM orthogonal frequency division multiplexing, or orthogonal frequency

division modulation (preferred)O-FDMA orthogonal frequency division multiple accessOOB out of bandOOK on-off keyingO-PSK offset phase-shift keyingPA power amplifierPAE power-added efficiencyPAM pulse amplitude modulationPAN personal area networkPAPR peak-to-average power ratioPD phase detectorpdf probability density functionPDF envelope probability density functionPDMA polarization division multiple accessPFD phase-frequency detectorPG process gainPLL phaselock loopPM phase modulationppm part per millionpPSK pure PSKPR partial responsePRN pseudo-random numberPSD power spectral densityPSK phase-shift keyingQ quadrature axis; quadrature signal componentQAM quadrature amplitude modulationQCC quadratic congruence codesQD quadrature demodulatorQM quadrature modulatorQPSK quaternary phase-shift keyingRBW resolution bandwidthRF radio frequencyRKE remote keyless entry

Definitions and acronyms xxiii






RLL run-length limitedRSC recursive systematic convolutional (encoder)RSSI received signal-strength indicationRTS request to sendRX receiverSAR specific absorption rateSC suppressed carrierSC-FDMA single carrier frequency division multiple accessSFH slow frequency hoppingSLPF superposition lowpass filterSNR signal-to-noise ratioSps symbols per secondSRC spectral raised cosineSRRC spectral square-root raised cosineSS spread spectrumSSQAM step-square quadrature amplitude modulationTDM time division multiplexingTDMA time division multiple accessTETRA TErresTrial RAdio, a TDMA network designed for public service

applicationstQAM triangular arrangement of QAM constellation pointsTSAD time-shift angle demodulatorTX transmitterTXP transmitter powerUHF ultra high frequency (300–3000 MHz)UMTS universal mobile telephone serviceVCO voltage-controlled oscillatorVHF very high frequency (30–300 MHz)WBFM wideband frequency modulationW-CDMA wideband code division multiple accessWLAN wireless local area network

xxiv Definitions and acronyms






Terminology and notation

There are two conventions followed in the use of terminology within this book. They are:

1. Terms and ratios in linear units are in lower case letters2. Terms and ratios in logarithmic (dB) units are in UPPER CASE letters

One of the tendencies I have noted in the literature is that this separation is rarely applied.This forces a reader to infer what an author is trying to convey from either the widercontext of the writing, or from long contemplation after finishing reading in order todiscern the author’s intent. Both of these are causes for ambiguity, and at a minimum areopportunities for misunderstanding. In any work that is trying to teach principles andconcepts this is certainly bad.

I have tried to contribute toward adding clarity by following these two conventions.This means that within each discussion if needed I have invented a lower case or uppercase term as appropriate. While a reader who goes directly to a particular chapter in thisbook and does not read this page might think that the unconventional notation may be atypographical error, I can assure you that this is very deliberate on my part.

I hope that these conventions actually do contribute to additional clarity in the under-standing of wireless communications signals.

List of terms new in this book

BWFSK modified Carson’s Rule result for estimating FSK signal bandwidth, withunits of frequency. (This does not follow the convention: capitalized BW isthe traditional acronym for bandwidth.)

cp cyclic prefix factor, value is between 0 and 1cPSK conventional PSK, a QAM signal with envelope variations where the signal

constellation is restricted to points on the unit circleedr envelope dynamic range, the ratio of peak signal amplitude over minimum

signal amplitudeEDR decibel conversion of edrγ B/C, the inverse of channel capacity densityibend individual bit energy to noise density ratio, a descriptive name for Eb/N0

IBEND decibel conversion of ibendpapr peak to average power ratioPAPR decibel conversion of papr






pPSK pure PSK, a constant envelope signal modulated solely in phasesnr direct ratio of signal power over noise power in a specified bandwidthSNR decibel conversion of snrU channel capacity utilization factor, value is between 0 and 1ψPE power efficiency, one property of a signal constellation

xxvi Terminology and notation






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