A novel low-complexity transmission power adaptation in MC-CDMA systems with a-MRC receiver over Nakagami-m fading channels

In this paper, we propose a novel low-complexity transmission power adaptation with good bit error rate (BER) performance for multicarrier code-division multiple-access (MC-CDMA) systems over Nakagami-m fading channels. We first propose a new receiver called ath-order-maximal-ratio-combining (a-MRC) receiver with which the receiver power gain for the nth subcarrier is the ath (a𕟳) power of the corresponding channel gain. Incorporating the a-MRC receiver, we then propose a new transmission power adaptation scheme where the transmission power is allocated over all the N subcarriers according to the subchannel gains and the transmitter adapts its power to maintain a constant signal-to-interference-plus-noise (SINR) at the receiver. The proposed scheme has a significant performance gain over the nonadaptive transmission scheme over both independent and correlated fading channels. Moreover, the proposed scheme keeps good BER performance while it is much simpler than the previous power control-adaptation schemes. Copyright © 2008 John Wiley & Sons, Ltd.