This book amplitude modulation, single side-band communication, frequency modulation, communication means, digital communications, network communications, transmission lines, wave transmission, aerial, wave guide and radar, microwave and laser, television, optical fiber, etc. It involves many new technologies in the field of communications such as Bluetooth, Wi-Max, DTV, DSP, HD-Radio, etc. It can be used as a textbook for undergraduates who major in electronic information engineering and communications engineering, and used for reference by technicians in related fields.