Performance analysis on complementary coded cdma systems for uplink transmission with different detection schemes

Abstract

newline he CC-CDMA system is unique due to an excellent orthogonality among transmitting codes, even in asynchronous uplink channels. CC-CDMA upgrades conventional CDMA in terms of interference resistance in both synchronous and asynchronous communication. CC-CDMA can offer attractive isotropic Multi-Access Interference (MAI) free operation for wireless applications. The main motivation behind this thesis is to evaluate the BER performance of uplink CC MC-CDMA system and to perform suitable BER analysis for different fading channels in asynchronous communication. Reliable multiuser communication using CDMA is required to overcome the fall in BER performance, limiting the capacity and maximum data rate offered to the end users. Therefore, it is more vital to use proficient multiuser techniques for CC MC-CDMA system. In CC MC-CDMA system, MAI disturbs the orthogonality of the CCs used in uplink asynchronous transmission. In multipath environments, the transmitted signals undergo severe multipath distortion leading to Multipath Interference (MPI). In MIMO CC-CDMA systems operating under frequency selective fading channels, multi antenna interference results in degradation in system performance and diversity gain achievable in multiuser communication. In order to reduce the MAI in uplink asynchronous transmission, the performance of CC MC-CDMA system is investigated using different sub-optimal interference cancellation techniques. Also, analyses on the system performance with different receiver architectures for MIMO CC MC-CDMA systems operating under varying frequency selective fading channels is performed. Also, investigation on the performance of SISO and MIMO CC-MC-CDMA using different pre-equalization schemes for uplink data transmission to achieve improved Bit Error Rate (BER) and user capacity is done