Power Constrained, Power Adaptive, Decode and Forward Relay Selection Policy Design and Performance Analysis

Abstract

Decode-and-forward (DaF) or amplify-and-forward (AaF) relay based cooperative communication systems have been widely studied in the literature. It has been proved that relay-assisted device to device (D2D) communication can improve network performance. In this paper, a novel power adaptive, probability based relay selection policy (PA-PBRSP) is proposed for a four node relay assisted D2D cooperative communication network. In it, a power adaptive decode-and-forward (PADaF) relay whose average transmit power is constrained, adapts its transmit power and gain before encoding the signal and forward it to the destination. For the proposed policy, fading averaged symbol error rate (FASER) performance is analyzed. Specifically, analytical expressions for exact FASER and its upper bound are derived when M-ary phase shift keying (MPSK), and M-ary quadrature amplitude modulation (MQAM) schemes are employed. In order to validate the analytical results, Monte-Carlo simulations are performed for both the modulation schemes. To quantity the performance gains delivered by PA-PBRSP, the results of the proposed relaying policy are compared with the benchmark policies. Various numerical results that we obtained reveal that the proposed policy delivers FASER which is several times lower than the FASER of the benchmark relaying policies. This motivates use of PA-PBRSP policy in modern cooperative wireless networks.