Enhance Capacity of CDMA Network

Abstract

CDMA cellular mobile systems find acceptance particularly in regional centers where there are large geographical areas to cover. The capacity of a CDMA system is limited by the reverse link. The reverse link uses uncorrelated, non-orthogonal PN codes, which makes it limited by interference from other users. In order to achieve an increased capacity, the interference from users needs to be reduced. This can be achieved by monitoring the voice activity detection (VAD) so that the transmitter is switched off during periods of no voice activity. This reduces the effective interference level by the reduced duty cycle of the transmitted signal. The interference can also be reduced by using antenna sectorization. The capacity of a CDMA cellular system is investigated taking into consideration both single cell and multicell. Adaptive sectorisation is attempted with finite beam switching as a means of improving the cell capacity. Results are obtained using a simulation that takes into account of the random nature of user population both in single cell and multicell.