Optimized Power Control and Resource Allocation in Grouped MC-CDMA Systems

This paper investigates an optimized dynamic power control for downlink grouped multi carrier-code division multiple access (MC-CDMA) systems to facilitate a high overall system capacity. In the grouped MC-CDMA system, we partition all the subcarriers into several groups with equal space to fully exploit frequency diversity. The optimal power control for maximum system mutual information is introduced based on the optimal subcarrier allocation. However, due to the polynomial problem of transmit power, the accurate solution cannot be obtained. Thankfully, Taylor series expansion enables us to arrive at the approximate optimal power control scheme. According to the analysis result, we propose an approximate optimal power allocation algorithm, which is demonstrated to perform much better than equal power allocation on system capacity.