Salient Features: First Chapter: General introduction to cellular mobile system with its evolution generation-wise is presented. Basic principle of mobile communication and architecture is also discussed in this chapter. Second Chapter: This chapter concern primarily with the problems of digital communication through multi- path fading channel and its channel characterization. Third Chapter: Basic principle of CDMA with coding and spread spreading of spectrum is discussed in this chapter. Problems with transmission and reception of data in AWGN channel are also discussed. Fourth Chapter: Advantages of CDMA over other multiple access techniques like FDMA and TDMA is studied and quantitative method of measurement of performance of these systems is presented in this chapter. Finally, the method of proper code selection for efficient communication is presented. Fifth Chapter: Concept of RAKE receiver in CDMA with single user and multi-user receiver and its effectiveness in receiving multi-path fading signal is presented.