Investigations on improving the performance of cdma communication systems using multiuser detection techniques

Abstract

Code Division Multiple Access CDMA is a flexible multiple newlineaccess method suitable for supporting many new services like speech data newlinevideo etcetera which are becoming increasingly important for 3G wireless newlinemobile network Besides supporting multiple applications future systems newlinehave to meet the enhanced performance and capacity requirements newlineA CDMA system with conventional receiver performance is newlinesignificantly degraded by Multiple Access Interference MAI and near far newlineeffect Moreover MAI becomes substantial as the number of interferers newlineincreases or their power increases This is because of the loss of orthogonality newlinebetween spreading codes used by each user due to multipath channel effects newlineThese problems can further hamper the carrier recovery techniques however newlinebe mitigated with multiuser detection techniques newline newline