A practical incremental relaying scheme with imperfect feedback for wireless networks

Implementing incremental relaying in a practical system is not a trivial task because it requires the destination node to provide feedback on success or failure of a transmission. In practice, the feedback may be affected by propagation impairments and collisions. In this case, the relay and the source should coordinate among themselves in the absence of perfect feedback information such that packet collision will not occur. In view of the challenge, this paper proposes a novel and practical incremental relaying scheme that deals with the imperfect feedback. The key idea is to have pessimistic source and optimistic relay. The proposed scheme is simple and easily implementable. Simulation results show that the proposed scheme can outperform amplify-and-forward (AF), as well as approaching the performance of an idealized incremental AF with perfect feedback information.