Performance Enhancement of Grouped MCCDMA-MIMO System through Power Control Using Water Filling Game Theory under Imperfect Channel State Condition

Abstract

Continuous increase in demand of wireless services such as voice, data and multimedia is fueling the need of spectrally efficient techniques in communication networks. The MCCDMA-MIMO, a system of Multi Carrier Code Division Multiple Access (MCCDMA) technique with multiple antennas at both the transmitter and receiver gets benefits of ability to adopt multiple access capability from MCCDMA technique, achieves high data rate from MIMO concepts and becomes a very attractive multiple access technique for the future wireless communication systems. But, the wireless channels in MCCDMA-MIMO networks are known to display significant variations across active users' subcarriers as well as among subcarriers of the same user due to simultaneous spectrum utilization. This leads to the undesirable Multiple-Access Interference (MAI) and Inters Carrier Interference (ICI), accordingly degrades the performance of the system. So, the interference mitigation methodology in the MCDMA-MIMO system has received a lot of attention in next generation mobile environment. The power control and sub carrier grouping methods have been long standing open solutions for capacity enhancement. The strategic choice of assigning the transmission power to each individual subcarrier in the MCCDMA-MIMO system is subjected to the knowledge of Channel State Information (CSI), which usually becomes imperfect due to the time varying nature of the channels. The goal of this paper is to allocate proper power to sub-carriers of MCCDMA-MIMO system by playing water filling game theory against the CSI errors to improve the performance of the system.