Buffer-Aided Max-Link Relay Selection in Amplify-and-Forward Cooperative Networks

Abstract

This paper investigates the outage performance of an amplify-and-forward (AF) relay system that exploits buffer-aided max-link relay selection. Both asymmetric and symmetric source-to-relay and relay-to-destination channel configurations are considered. We derive the closed-form expressions for the outage probability and analyze the average packet delays. We prove that the diversity order is between $N$ and $\hbox{2}N$ (where $N$ is the relay number) , corresponding to a relay buffer size between 1 and $\infty$ , respectively. We also analytically show the coding gain. Numerical results are given to verify the theoretical analyses.