Performance of CDMA systems with Walsh and PN coding

Abstract

Wideband CDMA method has been recently investigated for its using in the future communication systems. Such systems capacity depends on many factors, the main is multi-access interference (MAI). MAI~is an inherent CDMA property connected to correlation characteristics of codes used to access and to spreading. The influence on CDMA performance of these codes families and parameters is presented in this paper. The standard Gaussian approximation has been used for interference analysis. Bit error rate (BER) on detector output is a~measure of interference influence on transmission quality. It can be used for SNRi evaluation on receiver input for channel assignment and handover procedures. The results of interference analysis for the pseudo-noise sequences (M-sequences, Gold, de`Bruin and Jennings) as well as for the Walsh orthogonal mapping are presented in this paper.

Keywords

• PN spreading
• CDMA
• multi-access interference