While it encompasses a broad range of communications environments, this book should be of interest mainly to high-speed modem designers and developers. Although special care has been taken to ensure readability, the book is not easy. Its contents are more theoretical, in the tradition of the Russian school of engineering, than they are directly applicable. There are no cookbook recipes, although, with some effort, the approach of describing algorithms can be turned into workable solutions.

The book consists of six chapters and a two-page appendix that glances over the Hilbert transform. The chapters contain the really useful information. Chapter 1 introduces phase modulation and phase-difference modulation. The author tries to elucidate the benefits of using these types of modulation, although the approach he uses is not as convincing as it could be. The chapter also serves as a tutorial on phase modulation and phase-difference modulation. While chapter 2 builds on the information in chapter 1, it also relies on some background in statistical communications, a topic required for understanding chapter 3. High-order difference modulation occupies almost half of chapter 2. The rest of the chapter addresses such issues as optimum keying codes and algorithms for multiphase decoding. Chapter 3 deals with the coherent and quasicoherent processing of phase modulated signals, as well as phase-difference and quadrature amplitude modulation.

Chapter 4 describes optimum noncoherent processing of phase-difference signals. Chapter 5 examines the processing of phase-modulated signals by autocorrelation techniques. This is probably the most practically oriented chapter. Chapter 6, the final chapter, presents the means by which reliability of the transmission can be assessed, including error probabilities, signal-to-noise ratio estimates, and noise immunity.

One of the book’s weak points is that most references are to untranslated work by Russian researchers, and, as such, are of doubtful value to anyone lacking the corresponding language skills. This is unfortunate in a broader sense, since there is much valuable published work by Russian scientists and engineers that does not often get the wide audience it deserves. Although not always easy to follow, this book is solid as a theoretical (rather than practical) reference, and it provides a good opportunity for readers to get acquainted with the specific presentation style of some of the Russian schools of engineering.