Hop‐by‐hop Relay Selection strategy for multi‐hop relay networks with imperfect CSI

Abstract

A hop‐by‐hop relay selection (RS) strategy for multi‐hop decode‐and‐forward cooperative relay networks referred to as Max‐DS is proposed. In this method, RS in each stage is only based on the channel state information (CSI) to relays in the next stage. In each stage, relays that successfully receive and decode the message from the previous stage form the candidate set for relaying, and among them, the relay with the largest number of ‘good’ channels to the next stage is selected for retransmission. It is shown that the proposed method can be implemented in a distributed manner without the need for a central controller. The authors analyse the performance of the proposed method in terms of end‐to‐end outage probability in the case of imperfect CSI of which the case of perfect CSI is a special case. Numerical results are presented from analysis which closely match those obtained from simulation. The results are compared with those from several other RS strategies, and show significant improvements.