Analysis of diversity reception improvements in spread spectrum receivers

This paper describes how bearing estimation techniques may be applied to a direct sequence spread spectrum (DS-SS) system in order to provide an effective spatial diversity receiver. This structure is proposed as a method of increasing the capacity of a cellular code division multiple access (CDMA) system. Firstly, the subject of an optimum diversity system using bearing estimation is addressed. It is demonstrated that a N-element antenna diversity system improves the mean signal-to-noise ratio for a CDMA system in proportion to N, which can considerably improve bit error rate (BER) performance. The operation of the receiver in a cellular telephone network is discussed and the improvement in user capacity provided by such a system with perfect power control is shown