Spread Spectrum in Communication

The book is devoted to advanced radiocommunication, discussing the merits and operational aspects of spread spectrum signalling. Spread spectrum modulation is emerging as one of the most important tools for combatting a wide range of problems usually encountered in radiocommunication. For military applications the signalling is able to resist difficulties deliberately introduced by an enemy, such as jamming and eavesdropping. For civil application, the efficient signal multiplexing and multipath rejection capability is of great interest. The price paid however is the need for very complex processing of the radio signals. This task put great challenges on new technologies and design, and it is only recently that operational systems have started to emerge from the laboratories.

The book starts by comparing spread spectrum modulation and conventional modulation methods, and then discusses demodulation, which requires both special acquisition and synchronisation techniques. The electronic warfare scenario is introduced, discussing the principles of various spreading techniques and possible countermeasures. The coding for bandwidth spreading in a direct sequence spread spectrum system is treated by discussing the most common codes and their different figures of merit with respect to multipath, code division multiplexing and signal concealment. The book also illustrates the possible benefits, as well as limits to the use of new hardware technology to accomplish the various functions necessary for successful operation of a spread spectrum system. The effect of the propagation environment on spread spectrum is treated both analytically and through reported experiments and simulations. Finally the book considers the task of designing a complete communication network and discusses the usefulness and technology for additional interference suppressing techniques suitable to work with spread spectrum systems.