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ADAPTIVE COMMUNICATIONS AND THE BOOK LAYOUT In order to justify the content of the book and to make suggestions on how the book should be studied, we start with the generic block diagram of a digital communication system shown in Figure 1.1. The standard building blocks, information source, source encoder, encryptor, channel encoder and data modulator are used to produce a narrowband signal, for example, binary phase shift keying (BPSK), quaternary phase shift keying (QPSK) or M-ary quadrature amplitude modulation MQAM carrying information content. The spreading of the signal spectra is obtained by real or complex multiplication of the narrowband. | Adaptive WCDMA Theory And Practice. Savo G. Glisic Copyright 2003 John Wiley Sons Ltd. ISBN 0-470-84825-1 1 Fundamentals 1.1 ADAPTIVE COMMUNICATIONS AND THE BOOK LAYOUT In order to justify the content of the book and to make suggestions on how the book should be studied we start with the generic block diagram of a digital communication system shown in Figure 1.1. The standard building blocks information source source encoder encryptor channel encoder and data modulator are used to produce a narrowband signal for example binary phase shift keying BPSK quaternary phase shift keying QPSK or M-ary quadrature amplitude modulation MQAM carrying information content. The spreading of the signal spectra is obtained by real or complex multiplication of the narrowband signal by a code. After power amplification the signal will be transmitted by one antenna or by multiple antennae transmit diversity . After multipath propagation multiple replica of the transmitted signal will reach the receiver. In a number of parallel processors RAKE the receiver will try to independently demodulate a number of signal replicas. The first step is signal despreading of the number of multipath components. To do so a channel estimator is needed to estimate the delays and amplitudes of these components in order to be optimally combined in coherent RAKE combiner. Prior to combining cancelation of multiple access and multipath interference MPI may be performed in order to improve system performance. After signal combining the remaining signal processing including channel decoder decryptor and source decoder is performed. Separate block channel network characterizes the impact of fading noise network design and information broadcast from the network for control purposes. On the basis of side information obtained either from the network or channel estimator the receiver configuration control block from Figure 1.1 will put together the best possible receiver transmitter parameters or even change the .
