Synopsis Information Theory and technology has brought a boom in communication system. Contents of Information in signal and effect of noise on signal transmission form a subject of utmost significance for students and practicing engineers. The book has been designed as a text book for third and final year Bio-Technology/M.Sc. Electronics students. It also serves a basic resources material for research studies in advanced communication. Professor Triwari and Dr. Vibha Tripathi with their long teaching and research experiences give a masterly presentation of various aspects of signal and noise theory. The book begins with spectral analysis. Then it gives a detailed discussion of basic signal property for analysis probabilistic aspect of the signal and noise, exclusive noise analysis and information and coding theory. With suitable illustrative examples and solved problems it creates a superior insight about transmission theory.