Efficient power allocation schemes for MIMO cooperative relaying systems

Cooperative relaying technology is proved to be an efficient method to exploit the capacity of the multiple-input multiple-output (MIMO) wireless system. In this paper, the transmit power allocation (TPA) strategies for various relaying protocols are investigated for MIMO cooperative relaying systems. First, the TPA scheme for compress-and-forward (CF) protocol is proposed with closed-form by utilizing the Lagrange function. Second, a novel best node and antenna selection strategy is exploited for decode-and-forward (DF) relaying, which can improve the efficiency for the transmit power. Besides, the TPA scheme for amplify-and-forward (AF) protocol is analyzed. Simulation results show that the efficient TPA schemes can achieve significant gain by exploit the features of multihop transmission. Furthermore, compared with AF, DF, and hybrid decode-and-forward (HDF) protocols, the CF relaying can be used for coverage extension, which is a candidate technology for future LTE-A networks.