This book focuses on the principle of blind source separation (BSS) technology and its application in communication signal processing. This book first introduces the basic knowledge of BSS technology, and then introduces the whitening pre-processing algorithm of BSS and the source signal number estimation technology. The principles and implementation steps of various BSS algorithms are introduced in detail, and the simulation results of various algorithms are given. The application examples and experimental results of BSS technology in communication signal processing are given. The detailed derivation and simulation results of BSS algorithm principles are the features of this book, which is especially suitable for readers who are interested in learning BSS technology. The book can benefit researchers, engineers and graduate students in the fields of communications engineering and signal processing.