Adaptive sub channel grouping in MC-CDMA systems for 4G networks

Abstract

The Multi-Carrier Code Division Multiple Access (MC-CDMA) is becoming a very significant downlink multiple access technique for high-rate data transmission in the fourth generation wireless communication systems. In this paper an adaptive sub channel grouping (ASG) scheme is proposed. In this scheme channels are allocated to the users according to the CSI obtained, a channel will be allocated to that user who experiences least fading on that channel. In similar way all the channels are allocated to users and total number of channels allocated to one user forms one group. The total number of groups is equal to number of users and number of channels per group are different. The proposed algorithm reduces the required transmit power and yields a solution that maximizes the throughput. Simulations results are presented for 4G environment and it is found that the proposed ASG algorithm can significantly improve the system throughput as compared to conventional schemes of group formation where neighboring channels forms groups and number of channels per groups are same.