Network Coded Wireless Multicast with Advanced Receiver Capabilities

Abstract:
We consider wireless multihop networks with intrasession network coding and advanced physical layer techniques. In particular, we study the influence of multiuser decoding at receivers on the network utility maximization problem. To this end, we combine the polymatroid broadcast function model with the Gaussian compound multiple access channel (MAC) to model the information flow when multiple receivers decode messages from multiple transmitters. For this model, we formulate a network utility maximization problem and use a dual decomposition approach to separate the polymatroid flow subproblem, the scheduling and decoding assignment subproblem, and the compound MAC physical layer subproblem. The polymatroid flow and the compound MAC subproblems can be significantly simplified by exploiting their inherent polymatroid structure. For the scheduling and decoding assignment problem, we discuss the optimal solution, which results in an exhaustive search, and a simple greedy heuristic. In numerical simulations, we show a significant gain in network utility due to the advanced receiver capabilities compared to simple receivers.