An opportunistic network coding cooperative scheme for wireless uplink multi-relay cooperative networks

In this paper, an opportunistic network-coded cooperative scheme is proposed for the combination of network coding method and cooperative communication in wireless uplink multi-relay networks. Previous network-coded cooperative scheme always conducts network coding at relays in moderate-to-high signal-to-noise ratio region. Distinct from it, the proposed scheme determines either a direct cooperative mode or a network-coded cooperative mode at relays according to the channel qualities of the broadcast phase. Compared with the previous network-coded cooperative scheme, the proposed scheme achieves a performance gain in terms of both diversity order and system ergordic capacity without extra bandwidth resource consumption. Both theoretical analysis and simulations verify the validity and superiority of the proposed cooperative scheme.