数字通信：英文版

Preface

Acknowledgements

List of abbreviations

List of principal symbols

1 Digital communications overview

1.1 Electronic communications

1.2 Sources and sinks of information

1.3 Digital communications equipment

1.3.1 CODECs

1.3.2 Source,security and error control coding

1.3.3 Multiplexers

1.3.4 MODEMs

1.3.5 Multiple accessing

1.4 Radio receivers

1.5 Signal transmission

1.5.1 Line transmission

1.5.2 Radio transmission

1.6 Switching and networks

1.7 Advantages of digital communications

1.8 Summary

Part One Signals and systems theory

2 Periodic and transient signals

2.1 Introduction

2.2 Periodic signals

2.2.1 Sinusoids,cisoids and phasors

2.2.2 Fourier series

2.2.3 Conditions for existence,convergence and Gibb's phenomenon

2.2.4 Bandwidth,rates of change,sampling and aliasing

2.3 Transient signals

2.3.1 Fourier transforms

2.3.2 Practical calculation of Fourier transforms

2.3.3 Fourier transform pairs

2.3.4 Fourier transform theorems and convolution

2.4 Power and enegy sectra

2.5 Generalised orthogonal function expansions

2.5.1 Review of vectors

2.5.2 Vector interpretation of waveforms

2.5.3 Orthogonal and orthonormal signals

2.5.4 Evaluation of basis function coefficients

2.5.5 Error energy and completeness

2.6 Correlation functions

2.7 Summary

2.8 Problems

3 Random Signals and noise

3.1 Introduction

3.2 Probability theory

3.2.1 Conditional probabilities,joint Probabilities and Bayes's rule

3.2.2 Statistical independence

3.2.3 Discrete probability of errors in a data block

3.2.4 Cumulative distributions and probability density functions

3.2.5 Moments,percentiles and modes

3.2.6 Joint and marginal pdfs,correlation and covariance

3.2.7 Joint moments,correlation and covariance

3.2.8 Joint Gaussian raussian random variables

3.2.9 Addition of random variables and the central limit theorem

3.3 Random processes

3.3.1 Stationarity and ergodicity

3.3.2 Strict and loose sense Gaussian processes

3.3.3 Autocorrelation and power spectral density

3.3.4 Signal memory,decorrelation time and white noise

3.3.5 Cross correlation of random processes

3.4 Summary

3.5 Problems

4 Linear systems

4.1 Introduction

4.2 Linear systems

4.2.1 Properties of linear systems

4.2.2 Importance of linear systems

4.3 Time domain description of linear systems

4.3.1 Linear differential equations

4.3.2 Discrete signals and matrix algebra

4.3.3 Continuous signals,convolution and impulse response

4.3.4 Physical interpretation of y(t)=h(t)*x(t)

4.3.5 Step response

4.4 Frequency domain description

4.5 Causality and the Hibert transform

4.6 Random signals and linear systems

4.6.1 Power spectral densities and linear systems

4.6.2 Noise bandwidth

4.6.3 Pdf of filtered noise

4.6.4 Spectrum analysers

4.7 Non-linear systems and transformation of random variables

4.7.1 Rayleigh pdf

4.7.2 Chi-square distributions

4.8 Summary

4.9 Problems

Part Two Digital communications principles

5 Sampling,multiplexing and PCM

5.1 Introduction

5.2 Pulse modulation

5.3 Sampling

5.3.1 Natural and flat topped sampling

5.3.2 Baseband sampling and Nyquist's criterion

5.3.3 Aliasing

5.3.4 Practical sampling,reconstruction and signal to distortion ratio

5.3.5 Bandpass sampling

5.4 Analogue pulse multiplexing

5.5 quantised PAM

5.6 Signal to quantisation noise ration(SNqR)

5.7 Pulse code modulation

5.7.1 SNqR for linear PCM

5.7.2 SNR for decoded PCM

5.7.3 Companded PCM

5.7.4 PCM multiplexing

5.8 Bandwidth reduction techniques

5.8.1 Delta PCM

5.8.2 Differential PCM

5.8.3 Adaptive DPCM

5.8.4 Delta modulation

5.8.5 Adaptive delta modulation

5.9 Summary

5.10 Problems

6 Baseband transmission and line coding

6.1 Introduction

6.2 Baseband centre point detection

6.2.1 Baseband binary error rates in Gaussian noise

6.2.2 Multilevel baseband signalling

6.3 Error accumulation over multiple hops

6.4 Line coding

6.4.1 Unipolar signalling

6.4.2 Polar signalling

6.4.3 Dipolar signalling

6.4.4 Bipolar alternate mark inversion signalling

6.4.5 Pulse synchronisation and HDBn coding

6.4.6 Coded mark inversion(CMI)

6.4.7 nBmT coding

6.5 Multiplex telephony

6.6 Digital signal regeneration

6.6.1 PCM line

6.6.2 Equalisation

6.6.3 Eye diagrams

6.6.4 Crosstalk

6.7 Symbol Timing recovery

6.8 Repeater design

6.9 Digital transmission in local loop

6.10 Summary

6.11 Problems

7 Decision theory

7.1 Introduction

7.2 A priori,conditional and a posteriori probabilities

7.3 Symbol transition matrix

7.3.1 Binary symmetric channel

7.4 Bayes's decision criterion

7.4.1 Decision costs

7.4.2 Expected conditional decision costs

7.4.3 Optimum decision rule

7.4.4 Optimum decision threshold voltage

7.4.5 Average unconditional decision cost

7.5 Neyman-Pearson decision criterion

7.6 Summary

7.7 Problems

8 Optimum filtering for transmission and reception

8.1 Introduction

8.2 Pulse shaping for optimum transmissions

8.2.1 Intersymbol interference(ISI)

8.2.2 Bandlimiting of rectangular pulses

8.2.3 ISI-free signals

8.2.4 Nyquist's vestigal symmetry theorem

8.2.5 Raised cosine filtering

8.2.6 Nyquist filtering for rectangular pulses

8.2.7 Duobinary signalling

8.2.8 Partial response signalling

8.3 Pulse filtering for optimum reception

8.3.1 Matched filtering

8.3.2 Correlation detection

8.3.3 Decision instant SNR

8.3.4 BER performance of optimum receivers

8.3.5 Comparison of baseband matched filtering and centre point detection

8.3.6 Differences between matched filtering and correlation

8.4 Root raised cosine filtering

8.5 Equalisation

8.6 Summary

8.7 Problems

9 Information theory,source coding and encryption

9.1 Introduction

9.2 Information and entropy

9.2.1 The information measure

9.2.2 Multisymbol alphabets

9.2.3 Commonly confused entities

9.2.4 Entropy of a binary source

9.3 Conditional entropy and redundancy

9.4 Information loss due to noise

9.5 Source coding

9.5.1 code efficiency

9.5.2 Decoding variable length codewords

9.6 Variable length coding

9.6.1 Huffman coding

9.7 Source coding examples

9.7.1 Source coding for speech signals

9.7.2 High quality speech coders

9.7.3 Audio coders

9.7.4 String coding

9.8 Data encryption

9.8.1 The locked box analogy

9.8.2 Secrecy

9.8.3 Substitution and permutation

9.8.4 Confusion,diffusion and the unicity distance

9.8.5 Block ciphers and stream ciphers

9.8.6 Product ciphers

9.8.7 Data encryption standard

9.8.8 Public key encryption

9.8.9 Hash functions and OEAP

9.8.10 Hybrid public key/private key encryption and PGP

9.9 Authentication

9.10 Integrity

9.11 Digital Signatures

9.12 Summary

9.13 Problems

10 Error control coding

10.1 Introduction

10.1.1 Error rate control concepts

10.1.2 Threshold phenomenon

10.1.3 Applications for error control

10.2 Hamming distance and codeword wight

10.3 (n,k)block codes

10.3.1 Single parity check code

10.4 Probability of error in n-digit codewords

10.5 Linear group codes

10.5.1 Members of the group code family

10.5.2 Performance prediction

10.5.3 Error detection and correction capability

10.6 Nearest neighbour decoding of block codes

10.6.1 Hamming bound

10.7 Syndrome decoding

10.7.1 The generator matrix

10.7.2 Syndrome table for error correction

10.8 Cyclic codes

10.8.1 Polynomial codeword generation

10.8.2 Interleaving

10.9 Encoding of convolutional codes

10.9.1 Tree diagram representation

10.9.2 Trellis diagram

10.9.3 State transittion diagram

10.10 Viterbi decoding of convoltional codes

10.10.1 Decoding window

10.10.2 Sequential decoding

10.11 Practical coders

10.12 Concatenated coding and turbo codes

10.12.1 Serially concatenated codes

10.12.2 Parallel-concatenated recursive systematic convolutional codes

10.12.3 Turbo decoding

10.12.4 Turbo code performance

10.12.5 Other applications of the turbo principle

10.13 Summary

10.14 Problems

11 Bandpass modulation of a carrier signal

11.1 Introduction

11.2 Spectral and ower efficiency

11.3 binary IF modulation

11.3.1 Binary amplitude shift keying(and on-off keying)

11.3.2 Binary phase shift keying(and phase reversal keying)

11.3.3 Binary frequency shift keying

11.3.4 BFSK symbol correlation and Sunde's FSK

11.3.5 Comparison of binary shift keying techniques

11.3.6 Carrier recovery,phase ambiguity and DPSK

11.4 Modulation techniques with increased spectral efficiency

11.4.1 Channel capacity

11.4.2 M-symbol phase shift keying

11.4.3 Amplitude/phase keying and quadrature amplitude modulation

11.4.4 quadrature phase shift keying(QPSK)and offset QPSK

11.4.5 Minimum shift keying

11.4.6 Gaussian MSK

11.4.7 Trellis coded modulation

11.5 Power efficient modulation techniques

11.5.1 Multidimensional signalling and MFSK

11.5.2 Orthogonal frequency division multiplex(OFDM)

11.5.3 Optimum constellation point packing

11.5.4 Optimum constellation point boundaries

11.6 Data modems

11.7 Summary

11.8 Problems

12 System noise and communications link budgets

12.1 Introduction

12.2 Physical aspects of noise

12.2.1 Thermal noise

12.2.2 Non-thermal noise

12.2.3 Combining white noise sources

12.3 System noise calculations

12.3.1 Noise temperature

12.3.2 Noise temperature of cascaded subsystems

12.3.3 Noise factor and noise figure

12.4 Radio communication link budgets

12.4.1 Antenna gain,effective area and efficiency

12.4.2 Free space and plane earth signal budgets

12.4.3 Antenna temperature and radio noise budgets

12.4.4 Receiver equivalent input CNR

12.4.5 Multipath fading and diversity reception

12.5 Fibre optic transmission links

12.5.1 Fibre types

12.5.2 Fibre transmission systems

12.5.3 Optical sources

12.5.4 Optical detectors

12.5.5 Optical amplifiers

12.5.6 Optical repeater and link budgets

12.5.7 Optical FDM

12.5.8 Optical signal routers

12.6 Summary

12.7 Problems

13 Communication systems simulation

13.1 Introduction

13.2 Equivalent complex baseband representations

13.2.1 Equivalent baseband signals

13.2.2 Equivalent baseband systems

13.2.3 Equivalent baseband systems output

13.2.4 Equivalent baseband noise

13.3 Sampling and quantisation

13.3.1 Sampling equivalent baseband signals

13.3.2 Quantisation

13.4 Modeling of signals,noise and systems

13.4.1 Random numbers

13.4.2 Random digital symbol streams

13.4.3 Noise and interference

13.4.4 Time invariant linear systems

13.4.5 Non-linear and time varying systems

13.5 Transformation between time and frequency domains

13.5.1 DFT

13.5.2 DFS

13.5.3 DFS spectrum and rearrangement of spectral lines

13.5.4 Conservation of information

13.5.5 Phasor interpretation of DFS

13.5.6 Inverse DFS and DFT

13.5.7 DFT accuracy

13.6 Discrete and cyclical convolution

13.7 Estimation of BER

13.7.1 Monte Carlo simulation

13.7.2 Quasi-analytic simulation

13.8 Summary

Part Three Application

14 Fixed-point microwaver communications

14.1 Introduction

14.2 Terrestrial microwaver links

14.2.1 Analogue systems

14.2.2 Digital systems

14.2.3 LOS link design

14.2.4 Other propagation considerations terrestrial links

14.3 Fixed-point satellite communications

14.3.1 Satellite frequency bands and orbital spacing

14.3.2 Earth station look angles and satellite range

14.3.3 Satellite link budgets

14.3.4 Slant path propagation considerations

14.3.5 Analogue FDM/FM/FDMA trunk systems

14.3.6 digital TDM/PSK/TDMA trunk systems

14.3.7 DA-TDMA,DSI and random access systems

14.3.8 Economics of satellite communications

14.3.9 VSAT systems

14.3.10 Satellite switched TDMA and onboard signal processing

14.4 Summary

14.5 Problems

15 Mobile and cellular radio

15.1 Introduction

15.1.1 private mobile radio

15.1.2 Radio paging systems

15.2 Mobile radio link budget and channel characteristics

15.2.1 Prediction of median signal strength

15.2.2 slow and fast fading

15.2.3 Dispersion,frequency selective fading and coherence bandwidth

15.2.4 Multipath modeling and simulation

15.3 Nationwide cellular radio communications

15.3.1 Introduction

15.3.2 Personal cordless communication

15.3.3 Analogue cellular radio communication

15.3.4 Cell sizes

15.3.5 System configuration

15.4 Digital TDMA terrestrial cellular systems

15.4.1 TDMA systems

15.4.2 TDMA data format and modulation

15.4.3 Speech and channel coding

15.4.4 Other operational constraints

15.4.5 Trunked radio for paramilitary use

15.5 Code division multiple access(CDMA)

15.5.1 The CDMA concept

15.5.2 CDMA receiver design

15.5.3 Spreading sequence design

15.5.4 Data modulation

15.5.5 CDMA multipath processing

15.5.6 The cdmaOne system

15.5.7 Frequency hopped transmission

15.6 Mobile satellite based systems

15.7 Third generation mobile cellular standards

15.7.1 Mobile data transmission

15.7.2 3G developments

15.7.3 Wideband CDMA

15.8 Summary

15.9 Problems

16 Video transmission and storage

16.1 Introduction

16.2 Colour representation

16.3 Conventional TV transmission systems

16.3.1 PAL encoding

16.3.2 PAL television receiver

16.3.3 Other encoding schemes

16.4 High definition TV

16.4.1 What is HDTV?

16.4.2 Studio standards

16.4.3 Transmissions

16.5 Digital video

16.6 Video data compression

16.6.1 Run length coding

16.6.2 Conditional replenishment

16.6.3 Transform coding

16.7 Compression standards

16.7.1 COST 211

16.7.2 JPEG

16.7.3 MPEG-1 and MPEG-2

16.7.4 MPEG-4

16.7.5 MPEG-7

16.7.6 H.261 and H.263

16.7.7 Model based coding

16.8 Digital video broadcast

16.9 Packet video

16.10 Summary

16.11 Problems

Part Four Networks

17 Metwork applications,topologies and architecture

17.1 Introduction

17.2 Network applications

17.3 Network function

17.4 Network classification

17.5 Switched network topologies and representation

17.5.1 Star or hub

17.5.2 Tree

17.5.3 Mesh

17.5.4 Matrix representation

17.6 generic network switching philosophies

17.6.1 Circuit switching

17.6.2 Message switching

17.6.3 Packet switching

17.7 Broadcast network topologies

17.7.1 Bus or multidrop

17.7.2 Passive ring

17.7.3 Active ring

17.8 Transmission media

17.9 Interconnected networks

17.10 User and provider network views

17.11 Connection-oriented and connectionless services

17.12 Layered network architectures

17.12.1 ISO OSI protocol reference model

17.12.2 Network layers in use

17.13 Summary

17.14 Problems

18 Network protocols

18.1 Introduction

18.2 Physical layer

18.2.1 A physical layer protocol-X.21

18.3 Data-link layer

18.3.1 Synchronisation

18.3.2 Error control

18.3.3 Flow control

18.3.4 A data-link protocol-HDLC

18.4 Network layer

18.4.1 Routing

18.4.2 Congestion control

18.4.3 Error control

18.4.4 Quality of service

18.4.5 A connection-oriented network level protocol-X.25 PLP

18.4.6 A connectionless network level protocol(CLNP)

18.4.7 Use of primitives

18.5 Transport layer

18.5.1 Message segmentation and reassembly

18.5.2 Multiplexing and parallel virtual circuit transmission

18.5.3 End-to-end error and flow control

18.5.4 Use of well known and ephemeral ports

18.5.5 A Transport level protocol-TP4

18.6 Session layer

18.6.1 Session connection,maintenance and release

18.6.2 Dialogue supervision

18.6.3 Recovery

18.6.4 A session level protocol-ISO-SP

18.7 Presentation layer

18.7.1 Translation between local and transfer syntaxes

18.7.2 Abstract syntax notation 1(ASN.1)

18.7.3 A presentation level protocol-ISO-PP

18.8 Application layer

18.9 Non-ISO protocol stacks

18.10 Summary

18.11 Problems

19 Network performance using queueing theory(M.E.Woodard)

19.1 Introduction

19.1.1 The arrival process

19.1.2 Queueing systems

19.2 The M/M/1 queue

19.2.1 The equilibrium probabilities

19.2.2 Performance measures

19.3 The M/M/1/N queue

19.3.1 General Markovian queueing equations

19.3.2 The M/M/N/N queue

19.3.3 The M/M/N/N/K queue

19.3.4 M/M/N/N+J queue(Erlang-C equation)

19.3.5 Distribution of waiting times

19.4 M/M/N/K/K queue:queueing behaviour in a mobile communication system

19.4.1 Speech source model

19.4.2 Equilibrium probability

19.5 Summary

19.6 Problems

20 Switched networks and WANs

20.1 Introduction

20.2 WAN characteristics and classification

20.3 Application of graph theory to core networks

20.3.1 Topology,cost and capacity matrices

20.3.2 Network capacity

20.3.3 Network connectivity

20.4 The UK public network

20.4.1 The traditional analogue network

20.4.2 The modern digital network

20.5 Multiplexing

20.5.1 The plesiochronous digital hierarchy

20.5.2 SDH and SONET

20.6 Circuit switching

20.6.1 Space switching

20.6.2 Time switching

20.6.3 Time-space-time and space-time-apace switching

20.6.4 Multi-stage space switches

20.6.5 Switch connectivity

20.6.6 Concentration and expansion

20.6.7 Switch design

20.6.8 Probability of blocking

20.6.9 Circuit switched data over the PSTN

20.7 Packet switching

20.7.1 Packet switched data over the PSTN

20.7.2 Packet switching

20.8 Integrated services digital network(ISDN)

20.8.1 ISDN structure

20.8.2 Basic and primary rate access

20.8.3 ISDN services

20.9 Signalling

20.9.1 In-channel and common channel signaling

20.9.2 Signalling system No.7

20.10 Asynchronous transfer mode and the broadband ISDN

20.10.1 Transport mechanism

20.10.2 Service classes

20.10.3 Connection admission control

20.10.4 Access protocols

20.10.5 Synchronous versus asynchronous transfer modes

20.10.6 ATM versus IP

20.11 Access technologies

20.11.1 Digital subscriber line

20.11.2 Fibre

20.11.3 Cable

20.11.4 Broadband fixed wireless access

20.11.5 Commparison of access network technologies

20.11.6 Convergence of access network services

20.12 Summary

20.13 Problems

21 Broadcast networks and LANs

21.1 Introduction

21.2 LAN topologies

21.3 LAN protocol stack

21.3.1 Fixed access multiplexing

21.3.2 Polling

21.3.3 Token passing

21.3.4 Contention

21.4 Popular wired-LAN standards

21.4.1 Ethernet(IEEE 802.3)

21.4.2 Token ring(IEEE 802.5)

21.5 Wireless LANs

21.5.1 WLAN(IEEE 802.11)

21.5.2 HIPERLAN

21.6 Wireless personal area networks

21.6.1 Bluetooth(IEEE 802.15.1)

21.6.2 Ohter IEEE 802.15 PAN technologies

21.7 Home networking technologies

21.7.1 Wired home networsks

21.7.2 Wireless home networks

21.8 Residential Rateways

21.9 Summary

21.10 Problems

Appendix A Tabulated values of the error function

Appendix B Summations of common series

Appendix C Internationl Apphaber No.5

Appendix D LAN/MAN example

Standards

WWW addresses

Bibliography

Index