Performance Enhancement of MC-CDMA System through STTC based STBC Site Diversity

The combination of multiple antennas and multicarrier code division multiple access (MC-CDMA) is a strong candidate for the downlink of future mobile communications. The study of such systems, in scenarios that model real life transmissions is an additional step towards an optimised achievement. Nevertheless, when transmitting over fading channel multi-cell interference occurs and this degrades the performance of the system. Site diversity technique is applied to the system to overcome multi-cell interference. Due to non orthogonality of spreading codes multi-cell interference is not completelyeradicated. To overcome this problem, spreading codes are assigned to each base station. Space time trellis code (STTC) site diversity with multiple input multiple output (MIMO) technique was introduced to reduce multi-cell interference further. In this paper balanced STTC (B-STTC) site diversity is proposed to improve the performance of MC-CDMA system and is extended to STTC based STBC site diversity. Simulation result shows that STTC based STBC site diversity outperforms B-STTC site diversity.