Pulse Shaping and Detection

This chapter explores various techniques of filtering and pulse shaping to minimise intersymbol interference (ISI). It provides a brief discussion of the core functions of a digital communication receiver, including a detailed treatment of the matched filter for optimum pulse detection in the presence of additive white Gaussian noise. The chapter also provides a clear discussion of various anti-ISI filtering techniques, including Nyquist, raised cosine, root raised cosine, and duobinary. It points out that Shannon’s channel coding theorem merely tells us that it is possible to have error-free transmission at the maximum bit rate given by the information capacity law. The chapter briefly considers the measures of equalisation, matched filtering, and clock extraction used at the receiver to optimise the detection of a transmitted pulse sequence in the presence of channel distortion and noise.