Impact of Relay Selection Overhead in Cooperative Diversity Protocols

Cooperative diversity employs relays to assist source-destination transmissions and has shown to improve link outage probability in multipath fading environments. In this paper, we model relay selection as a semi-Markov process to analyze the impact of relay selection overhead on throughput, delay, and jitter in a simple scenario. Results show that the selection overhead can significantly reduce benefits of reactive relay selection if data frames are small or only few nodes overhear data. In such scenarios, relaying with a preassigned relay can be more beneficial.