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Power Efficient Relay Selection and Diversity-Multiplexing Tradeoff in Two-way Relaying Networks

Jie Yang1,2 and Xuehong Cao2
1.Department of Communication and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing, 210003, China
2.Department of Communication Engineering, Nanjing Institute of Technology, Nanjing, 211167, China

Abstract—Two-way amplify-and-forward (AF) relaying networks have been widely studied because of its simplicity and high spectral efficiency. In this paper, we investigate the relay selection problem and the diversity-multiplexing tradeoff (DMT) for two-way AF relaying systems over independent flat Rayleigh fading channels. We first derive the closed-form expression of the minimum total transmit power under the predefined data rate requirements. Based on the minimum total transmit power, we propose a simple relay selection which only requires user-relay channel state information (CSI). We proved that the proposed relay selection scheme can achieve the same DMT performance as obtained by the popular outage-optimal two-way opportunistic relaying scheme. Simulation results demonstrate that the proposed scheme can significantly decrease the power consumption compared with random relay selection and other schemes.

Index Terms—Two-way, amplify-and-forward, relay selection, power allocation

Cite: Jie Yang and Xuehong Cao, "Power Efficient Relay Selection and Diversity-Multiplexing Tradeoff in Two-way Relaying Networks," Journal of Communications, vol. 9, no. 8, pp. 644-650, 2014. Doi: 10.12720/jcm.9.8.644-650