Coordinated Hybrid Automatic Repeat Request; Extended Version

TL;DR

This paper introduces a coordinated HARQ scheme that reallocates spectrum from successfully decoded users to others, enhancing network reliability and fairness across various antenna configurations.

Contribution

It proposes a novel coordinated HARQ method that improves outage probability and fairness by spectrum sharing among users, validated through diverse antenna setups.

Findings

Diversity gain increases from M to (J+1)(M-1)+1 with the scheme

The approach improves network outage probability

Enhanced fairness among users

Abstract

We develop a coordinated hybrid automatic repeat request (HARQ) approach. With the proposed scheme, if a user message is correctly decoded in the first HARQ rounds, its spectrum is allocated to other users, to improve the network outage probability and the users' fairness. The results, which are obtained for single- and multiple-antenna setups, demonstrate the efficiency of the proposed approach in different conditions. For instance, with a maximum of M retransmissions and single transmit/receive antennas, the diversity gain of a user increases from M to (J+1)(M-1)+1 where J is the number of users helping that user.