Cooperative Hybrid ARQ Protocols: Unified Frameworks for Protocol Analysis

TL;DR

This paper introduces unified analytical frameworks for cooperative hybrid-ARQ protocols, enabling comparison of their performance in terms of throughput and outage probability under various network conditions.

Contribution

It develops two unified frameworks to analyze and compare decode-and-forward and amplify-and-forward cooperative HARQ protocols.

Findings

Frameworks evaluate maximum throughput and outage probabilities.

Protocols' performance depends on SNR, relay location, and delay constraints.

Unified analysis facilitates optimal protocol parameter selection.

Abstract

Cooperative hybrid-ARQ (HARQ) protocols, which can exploit the spatial and temporal diversities, have been widely studied. The efficiency of cooperative HARQ protocols is higher than that of cooperative protocols, because retransmissions are only performed when necessary. We classify cooperative HARQ protocols as three decode-and-forward based HARQ (DF-HARQ) protocols and two amplified-and-forward based (AF-HARQ) protocols. To compare these protocols and obtain the optimum parameters, two unified frameworks are developed for protocol analysis. Using the frameworks, we can evaluate and compare the maximum throughput and outage probabilities according to the SNR, the relay location, and the delay constraint for the protocols.