Energy-Efficient Joint Power Allocation and Relay Selection in Bit Error Rate Constrained Two-Way Relay Network

In this paper, the authors have proposed energy efficient power allocation and relay selection scheme in a two-way amplify-and-forward (AF) relay under bit error rate (BER) constrained network. They have derived an expression for the overall BER for Rayleigh fading channel. Based on minimum power consumption in the network, the authors have addressed the problem of power allocation by converting geometric programming to a convex optimization problem. A closed form solution of power allocation is found, which aims at minimizing total transmit power for the overall BER constrained network. The authors have evaluated minimum total transmit power for two-way AF relay network. Based on minimum total transmit power, a novel relay selection scheme has been proposed. Simulation results demonstrate that the proposed two-way power allocation and relay selection scheme can significantly minimize power consumption under BER constrained network as compared to the existing relay transmission. The proposed power allocation scheme gives 3 dBW gain than one-way relay transmission. The proposed relay selection method also outperforms the random relay selection by 24 dBW. The simulation results are corroborated with the analytical result