The Impact of Channel Feedback on Opportunistic Relay Selection for Hybrid-ARQ in Wireless Networks

TL;DR

This paper introduces a decentralized relay selection protocol with channel feedback strategies that enhance hybrid-ARQ performance in dense wireless networks, achieving throughput comparable to centralized methods.

Contribution

It proposes a novel decentralized relay selection protocol with adaptive modulation and channel feedback, improving throughput without centralized coordination.

Findings

Throughput approximation and maximization analysis

Simulation results show comparable performance to centralized methods

Adaptive modulation enhances relay selection efficiency

Abstract

This paper presents a decentralized relay selection protocol for a dense wireless network and describes channel feedback strategies that improve its performance. The proposed selection protocol supports hybrid automatic-repeat-request transmission where relays forward parity information to the destination in the event of a decoding error. Channel feedback is employed for refining the relay selection process and for selecting an appropriate transmission mode in a proposed adaptive modulation transmission framework. An approximation of the throughput of the proposed adaptive modulation strategy is presented, and the dependence of the throughput on system parameters such as the relay contention probability and the adaptive modulation switching point is illustrated via maximization of this approximation. Simulations show that the throughput of the proposed selection strategy is comparable to that yielded by a centralized selection approach that relies on geographic information.