Scientific paper ID 878 : 2013/3

Realization of multiple access in cellular systems, it is necessary to solve many problems of theoretical and practical character. Among them, the most important is possible to separate the following areas:

- selection of criteria for the quality of functioning of cellular systems,

- selection of criteria and the construction of regular methods for calculating systems of complex signals,

- study of the efficiency and noise resistant of different types of systems with Code Division Multiple Access(CDMA),

- study the issues of synchronization in CDMA systems,

- analysis of the effectiveness of different methods of transmission of discrete information in the cellular systems, and methods for the transmission of continuous communications.

In accordance with the above, in this paper is considered CDMA system using Walsh codes for spread spectrum of the transmitted signal. The system combines these Walsh codes with two pseudo-noise code for each communication channel, thereby to build different channels. Since the spread is not uniform across the width of the frequency band they are used jointly with the PN code