Network coding-based block acknowledgement scheme for wireless regenerative relay networks

This paper is concerned with block acknowledgement (ACK) mechanisms in wireless regenerative relay networks. In an N -relay network, a total of (2N + 1) block ACK packets is required to acknowledge the data transmission between source and destination nodes via the N relay nodes. In this paper, we propose a block ACK scheme based on network coding (NC) to significantly reduce the acknowledgement overheads byN block ACK packets. In addition, this achieves a reduction ofN(N−1) computational operators. Particularly, we derive the error probability of the determination of the packets to be retransmitted at the source and relays, which shows that the NC-based scheme also improves the reliability of block ACK transmissions. Furthermore, asymptotic signal-to-noise (SNR) scenarios for forward links are considered and a general expression of error probability in multi-relay networks is derived for each SNR scenario. Finally, simulation results are presented to verify the analytical findings and demonstrate a lower number of data retransmissions for a higher system throughput. Q.-T. Vien, B. G. Stewart, and H. Tianfield are with School of Engineering and Built Environment, Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, UK. Email: {quoctuan.vien;b.stewart;h.tianfield}@gcu.ac.uk. H. X. Nguyen is with School of Engineering and Information Sciences, Middlesex University, The Burroughs, London NW4 4BT, UK. Email: [email protected]. J. Choi is with School of Engineering, Swansea University, Singleton Park, Swansea SA2 8PP, UK. Email: [email protected].