On practical network coded ARQ for two-way wireless communication
Hongyi Zhu, Xinghao Gu, Besma Smida, David J. Love · 2017
Network-coded (NCed) automatic repeat request (ARQ) techniques have been shown to provide significant throughput improvements over basic ARQ systems in two-way wireless systems. Most results derived so far, however, used the assumption of no extra overhead. In practical systems, NCed-ARQ requires more information exchange between base-station and end-nodes, and therefore it is crucial to study the impact of the extra-overhead on such systems. In this paper, we analyze the performance of a practical NCed-ARQ system. We assume M end-users wish to exchange information with a base-station. We derive first the average number of extra acknowledgments required to facilitate NCed-ARQ scheme. Then, we derive both downlink and uplink throughput expressions and study the tradeoff between feedback and re-transmission. Finally, we numerically optimize the throughput with respect to the number of end-users.