Transmission scheduling for PHY-layer wireless network coding

This paper addresses a transmission scheduling for wireless multi-hop network employing physical layer wireless network coding (PL-WNC). With PL-WNC, two distant nodes first transmit packets to an intermediate relay simultaneously, which then amplifies and forwards the received signal. The destination nodes decode the desired signals by using the a priori information which are their own packets or packets overheard from the other nodes. The achievable performance of PL-WNC depends not only on traffic pattern within a network but also on the probability for each destination node to have the a priori information for decoding the desired information. In this paper, we introduce a scheduling strategy for PL-WNC, which decides source-destination pairs of PL-WNC, taking account of traffic pattern as well as overhearing probability among nodes. The selected sources transmit packets only when the destinations are expected to have the a priori information with high probability. We define a parameter for each source node to decide whether it should transmit a packet when scheduled, and investigate its impact on the achievable throughput. Our simulation results show that our proposed scheduling significantly improves throughput of PL-WNC.