Adaptive Power Allocation for Decode-and-Forward MIMO-OFDM Relay System

In this paper, a two-hop MIMO-OFDM relay system with a decode-and-for-ward (DF) relay is considered, in which each terminal is equipped with multiple antennas. With the goal of maximizing the instantaneous capacity, a suboptimal power allocation algorithm under the total transmit power constraint is proposed. Since the independence of fading channel during each hop, subcarrier pairing strategy is given to further improve the system capacity. The simulation results show that the proposed suboptimal power allocation algorithm in this paper achieves a higher capacity than the uniform power allocation, and that subcarrier paring is an effective way to enhance the system capacity.