Analysis of Network Coded HARQ for Multiple Unicast Flows

作者：Larsson Peter^*; Smida Besma; Koike Akino Toshiaki; Tarokh Vahid

来源：IEEE Transactions on Communications, 2013, 61(2): 722-732.

DOI：10.1109/TCOMM.2012.121112.110202

• Network coding
• automatic repeat request (ARQ)
• cooperative systems
• Rayleigh channels

In this paper, we consider network coded (NCed) Hybrid-ARQ (HARQ) for multiple unicast flows. The main contribution of the paper is the derivation of throughput expressions for NCed HARQ with arbitrary number of users in identical i.i.d. channels amid packets for all users. We apply the result to Rayleigh fading channels and two packet combining schemes: incremental redundancy (IR) and chase combining (CC). We verify the analytical results with simulations and observe substantial SNR improvements over NCed ARQ and HARQ. The SNR gains in the moderate/high and low throughput regimes are mainly due to network coding and packet combining, respectively. For low/moderate SNRs, NCed HARQ with IR surpasses the CC performance. In addition, we introduce a novel re-transmission strategy that makes the network coding more efficient at low SNR.

• 出版日期2013-2