Abstract—The Channel State Information (CSI) plays a significant role in wireless Relay Selection (RS) systems. Due to the time variation of channels, the CSI in the data transmission phase may differ (i.e., is outdated) from that in the relay selection phase. Addressing this issue, the Decode-and-Forward (DF) Two-Way Relaying (TWR) network is considered, and the impact of outdated CSI on the system performance is investigated. The optimal max-min relay selection policy is proposed, which can be implemented easily by extending the distributed timer technique in practice. The expressions of outage probability are derived, and asymptotic analysis in the high SNR regime is also carried out, over Rayleigh fading channels. Numerical and simulation results collaborate the proposed studies.

Index Terms—Opportunistic relay selection, decode-and-forward, two-way relaying, outdated channel state information, outage probability

Cite: Jinglan Ou, Yawen Hu, Haoran Xu, Ge Wen, and Haowei Wu, “Opportunistic Relay Selection for Decode-and-Forward Two-Way Relaying under Outdated Channel State Information," Journal of Communications, vol. 11, no. 7, pp. 653-659, 2016. Doi: 10.12720/jcm.11.7.653-659