Modern Quadrature Amplitude Modulation Principles and Applications for Fixed and Wireless Channels

Size: px

Start display at page:

Download "Modern Quadrature Amplitude Modulation Principles and Applications for Fixed and Wireless Channels"

Kimberly Kelley
6 years ago
Views:

1 1 Modern Quadrature Amplitude Modulation Principles and Applications for Fixed and Wireless Channels W.T. Webb, L.Hanzo Contents PART I: Background to QAM 1 Introduction and Background Modulation methods History of QAM Determining the optimum constellation Coherent and non-coherent reception Clock recovery The Type I, II and III constellations Satellite links Odd-bit constellations QAM modem implementation Non-linear amplification Frequency selective fading and channel equalisers Filtering Advanced prototypes QAM for mobile radio Summary Outline of Topics 23 2 Communications Channels Fixed Communication Channels Introduction Fixed Channel Types Characterisation of Noise Telephone Channels Mobile Radio Channels Introduction Equivalent Baseband and Passband Systems Gaussian Mobile Radio Channel Narrow-band fading Channels Propagation Pathloss Law Slow Fading Statistics Fast Fading Statistics Doppler Spectrum Simulation of Narrowband Channels Frequency-domain fading simulation Time-domain fading simulation F &uumlller Algorithm of AWGN generation Wideband Channels Modelling of Wideband Channels Mobile Satellite Propagation Fixed-link satellite channels Satellite-to-mobile channels Summary 76 3 Introduction to modems Analogue to digital conversion Mapping Filtering 85

2 3.4 Modulation and demodulation Data recovery Summary 92 PART II: QAM for Gaussian Channels 4 Basic QAM Techniques Constellations for Gaussian channels General Pulse-Shaping Techniques Baseband Equivalent System Nyquist Filtering Raised-Cosine Nyquist Filtering The Choice of Roll-off Factor Optimum Transmit and Receive Filtering Characterisation of ISI by Eye-Diagrams Non-Linear Filtering Methods of Generating QAM Generating Conventional QAM Superposed QAM Offset QAM Non-Linear Amplification Methods of Detecting QAM Signals Threshold Detection of QAM Matched Filtered Detection Correlation receiver Linearisation of Power Amplifiers The Linearisation Problem Linearisation by Predistortion The Predistortion Concept Predistorter Description Predistorter Coefficient Adjustment Predistorter Performance Postdistortion of NLA-QAM The Postdistortion Concept Postdistorter Description Postdistorter Coefficient Adaptation Postdistorter Performance Non-differential coding for square QAM Differential coding for square QAM Summary Square QAM Decision Theory QAM modulation and transmission QAM Demodulation in AWGN QAM Demodulation in AWGN Summary Clock and Carrier Recovery Introduction Clock Recovery Times-two clock recovery Early-late clock recovery Zero crossing clock recovery Synchroniser Carrier Recovery Times-n carrier recovery Decision directed carrier recovery Frequency and phase detection systems Summary Basic Equaliser Techniques Introduction 197 2

3 7.2 Linear Equalisers Zero-Forcing Equalisers Least Mean-Squared Equalisers Decision-Directed Adaptive Equalisers Decision Feedback Equalisers Fast Converging Equalisers Least Squares Method Recursive Least Squares Method Cost-Function Weighting Recursive Correlation Update The Ricatti Equation of RLS Estimation Recursive Equaliser Coefficient Update Adaptive Equalisers for QAM Viterbi Equalisers Partial Response Modulation Viterbi Equalisation Summary Trellis Coded Modulation Introduction TCM Fundamentals PSK TCM QAM TCM TCM Under Phase Rotation Summary QAM Modems Introduction Transmission Bitrate Limits V.29 Modem Signal Constellation Training Signals Scrambling and Descrambling Channel Equalisation and Synchronisation V.32 Modem General Features Signal Constellation and Bit Mapping Non-Redundant 16-QAM Trellis-Coded 32-QAM Scrambler and Descrambler V.33 Modem General Features Signal Constellations and Bit Mapping Synchronising Signals Summary 278 PART III: QAM for Mobile Radio 10 Square QAM for fading channels QAM Performance QAM Performance Reference Assisted Coherent QAM Transparent Tone In Introduction Principles of TTIB TTIB Subcarrier Recovery TTIB Schemes Using Quadrature Mirror Filters Residual Frequency TTIB System Pilot Symbol Assisted Introduction 309 3

4 PSAM System Description Channel Gain Estimation PSAM Parameters PSAM Performance Summary Star QAM Introduction Star QAM Transmissions Differential coding Differential decoding Effect of oversampling Star 16-QAM Performance Trellis coded modulation for QAM Block Coding level TCM Bandwidth efficient coding results Overall coding strategy Square 16-QAM/PSAM/TCM Scheme Distorted Constellation Star QAM Introduction Distortion of the Star Amplitude Distortion Phase Variations Practical Considerations Introduction Hardware imperfections Quantisation Levels I-Q Crosstalk Oversampling Ratio AM-AM and AM-PM distortion Summary Timing Recovery for Mobile Radio Introduction Times-two clock recovery for QAM Early-Late Clock Recovery Modified Early-Late Clock Recovery Clock Recovery in the Presence of ISI Wideband Channel Models Clock Recovery in Two-Path Channels Case of τ nt Case of τ = nt Clock Recovery Performance in Smeared ISI Implementation Details Carrier recovery Summary Variable Rate QAM Introduction Variable QAM Constellations The RSSI Switching System Results The Error Detector Switching System Results Co-Channel Interference Application to a DECT-Type System Summary Wideband QAM Transmissions Introduction The RAKE Combiner 408 4

5 14.3 The Proposed Equaliser Linear Equaliser Iterative Equaliser System The One Symbol Window Equaliser The Limited Correction DFE Use of Error Correction Coding Diversity in the wideband system Summary 424 PART IV: Advanced QAM Techniques 15 Orthogonal Multiplex Systems Introduction Principles of QAM-FDM Modulation by DFT Transmission via Bandlimited Channels Generalised Nyquist Criterion OMPX Modem Implementations Reducing MDI by Block Extension Reducing MDI by Compensation Transient System Analysis Recursive MDI Compensation Adaptive Channel Equalisation Wide-Sense Orthogonality OMPX Bandwidth Efficiency Performance of an OMPX Scheme Summary Quadrature-Quadrature AM Introduction Q 2 PSK Q 2 AM Square 16-QAM Star 16-QAM Spectral efficiency Bandlimiting 16-Q 2 AM Results Summary Spectral Efficiency of QAM Introduction Efficiency in Large Cells Spectrum Efficiency in Microcells Microcellular Clusters System Design for Microcells Microcellular Radio Capacity Modulation Schemes for Microcells Summary QAM Speech Systems Introduction Modem Schemes GMSK Modulation PI/4 DQPSK Modulation Speech Codecs Adaptive Differential Pulse Code Modulation Analysis-by-synthesis speech coding The RPE-LTP Speech Encoder The RPE-LTP Speech Decoder Speech Quality Measures Discontinuous Transmission Channel Coding and Bit-mapping Speech Transmission Systems Packet Reservation Multiple Access PRMA performance 536 5

6 18.9 Summary Glossary Index 549 6

Quadrature Amplitude Modulation: From Basics to Adaptive Trellis-Coded, Turbo-Equalised and Space-Time Coded OFDM, CDMA and MC-CDMA Systems

Quadrature Amplitude Modulation: From Basics to Adaptive Trellis-Coded, Turbo-Equalised and Space-Time Coded OFDM, CDMA and MC-CDMA Systems by L. Hanzo, S.X. Ng, T. Keller, W.T. Webb Contents About the