Non Contiguous spectrum allocation in MC-CDMA systems for improving throughput

In this paper performance evaluation of non contiguous spectrum allocation technique i. e. adaptive sub channel grouping scheme (ASG) is carried out. In ASG technique non contiguous frequency bands forms groups for MC-CDMA systems in downlink transmission. In this scheme channels are allocated to the users according to the CSI obtained and number of channels allocated to one user forms one group., Autoregressive model is used for Rayleigh fading channel.Performance of ASG is evaluated for the test environment considering future Long Term Evolution (LTE) advanced standard, the 3GPP candidate for 4G. ASG scheme performance is compared with Improved scheme and Adaptive channel allocation(ACA) scheme. Simulations are carried out for three equalization schemes. It is found that the ASG scheme employing non contiguous spectrum allocation can significantly improve the system throughput as compared to contiguous schemes of group formation. BER performance of ASG scheme shows significant improvement over the other two schemes.