Digital transmission over bandlimited channels is studied. The concept of intersymbol interference (ISI) is described, and the Nyquist criterion for no ISI is derived. The raised cosine pulse, a widely used example of a practical communication pulse resulting in no ISI, is introduced. Both ideal and non-ideal bandlimited channels are considered. In addition, the power spectral density of digitally modulated signals is derived, and the spectral efficiencies of different digital modulation schemes are computed.

In Chapter 20 we study data transmission with constraints on the channel input. For example, how many bits per channel use can we transmit under constraints on the codewords? To answer this question in general, we need to extend the setup and coding theorems to channels with input constraints. After doing that we will apply these results to compute the capacities of various Gaussian channels (memoryless, with intersymbol interference and subject to fading).

This chapter introduces wireline communication, focusing on introducing key terminology, such as eye diagrams, intersymbol interference, noise, bit-error ratio, pulse response, non-return-to-zero modulation, pulse-amplitude modulation. The similarities and differences between electrical and optical links are discussed. Exemplary transceiver block diagrams are presented.

The fundamentals of analog and digital modulation techniques are presented in Chapter 6. The theoretical underpinnings of the world's most popular amplitude modulations, frequency modulations, and phase modulations are presented. The impact of pulse shape and filtering on bit error rate of a mobile communication system is demonstrated, where Doppler spread creates an irreducible bit error rate no matter how good the signal-to-noise ratio, yet is below the noise created by other aspects of the radio system. This led Europe to select GMSK for the pan-European 2G digital cellular standard, whereas the US selected a pi/4 PSK modulation method originated in Japan that allows both coherent and non-coherent demodulation and a graceful upgrade path for existing operators to adopt the new digital modulation with gradual base station changeouts over time.Capacity and Shannon's limit are defined and explained through numerous examples.