Feedback-Assisted Correlated Packet Transmission With a Helper

In this paper, we analyze the impact of source correlation on the diversity and coding gains of a retransmission system, where we aim to recover M erroneously received packets only by transmitting one helper packet utilizing the source correlation among the packets. This system is referred to as M-in-1 helper transmission. The helper packet is constructed simply by taking binary exclusive-OR of the M erroneously received information packets, notified via the feedback channel. To identify the tradeoff between source correlation and performance gain due to coding and diversity, we start our investigation with in-depth analyses on rate regions and outage probabilities with M = {2, 3}. We also evaluate the influence of unequal power and/or redundancy allocations between the helper and information packets. Finally, we provide the analytical results on achievable diversity order with arbitrary integer values of M. It is shown that M-in-1 helper transmission can always achieve Mth-order diversity. Furthermore, (M + 1)th-order diversity can be achieved with M being odd when the source correlation is very high; however, it cannot be achieved with M being even.

Irawan Ade, Matsumoto Tad

Publication type:
A1 Journal article – refereed

Place of publication:

admissible rate region, feedback, HARQ, helper, Outage probability, source correlation


Full citation:
A. Irawan and T. Matsumoto, “Feedback-Assisted Correlated Packet Transmission With a Helper,” in IEEE Transactions on Vehicular Technology, vol. 67, no. 5, pp. 4303-4315, May 2018,


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