Adaptive Subcarrier Grouping for Downlink MC-CDMA Systems with MMSE Receiver

This paper studies the problem of subcarrier grouping in the downlink of multi-carrier code division multiple access (MC-CDMA) systems with linear minimum mean square error (MMSE) receiver. Further, the problem is considered as combinatorial optimization problem. By theoretical analysis, an optimal subcarrier grouping scheme is proposed. Moreover, the proposed scheme is efficient in computational time. According to the instantaneous channel conditions, the proposed optimal scheme can be applied adaptively subcarrier grouping to maximize the system capacity. The simulation results show that the proposed scheme outperforms the conventional static schemes and is efficient in improving the system performance.