No abstract

Multi carrier CDMA (MC-CDMA) combines the CDMA and OFDM technologies together and potentially offers the advantages of both the technologies. It becomes a very attractive and promising multiple access technique for high-rate data transmission in the future wireless communication systems. To accomplish MC-CDMA aspirations with high capacity and low BER in multipath wireless environment, it is governed by two main functions: power allocation and subcarriers group assignment. Power allocation deals with the sharing of available power over each carrier to maximize the system capacity. Group assignment depicts selection of appropriate subcarriers to support data rate requirements of individual users. The Multiple Input and Multiple Output (MIMO) system is another technique to increase the transmission rate without expanding the signal bandwidth. This paper is focused on interference based subcarrier group assignment strategy for MCCDMA-MIMO system to maximize the system capacity and minimize BER by restricting interference noise using water filling game theory based power control algorithm. The sub carrier group assignment is implemented by selecting best sub carriers with maximum SINR value and user's QoS requirements. The performances of mean capacity and BER of the MCCDMA-MIMO system are evaluated with and without water filling algorithm.

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.