Digital transmission has assumed a greater role in transmission networks of the world as well as in terrestrial microwave and satellite systems. The aim of this book is to present in detail the theoretical and practical problems encountered in digital microwave transmission. Some aspects of the theoretical background of the field, for example the effect of wave propagation on high-speed transmission, direct regenerators, and digital phase-locked loops, treated in the first four chapters, have not yet been dealt with in other books. In the chapters which follow, the practical implications of subsystems, such as modulators, carrier recovery circuits together with baseband signal processing, and the auxiliary equipment, are described. The book is designed to be of use not only for those relatively new to the field, but more especially for researchers and graduate students who wish to augment their knowledge.