Performance Analysis of a Hop-by-Hop Relay Selection Strategy in Multi-Hop Networks

We propose and analyze a hop-by-hop relay selection strategy for multi-hop decode-and-forward (DF) cooperative relay networks. In this method, relay selection in each stage is based on the channel state information (CSI) to the relays in the following stage. More specifically, in each stage, relays that successfully receive and decode the message from the previous hop form the candidate set for relaying, and the best relay in this set is selected for retransmission to the next hop. As such, a central controller (CC) for the entire relay network is not required and this strategy can be implemented in a distributed manner. We analyze the performance of this method in terms of end-to-end outage probability and ergodic and effective ergodic capacities. Numerical results from analysis are shown to closely match those obtained from simulation. We also compare our results to those from existing relay selection strategies in the cases of perfect and imperfect CSI and demonstrate the advantages of the proposed method.