Practical Resource Allocation for the Broadcast Phase of Three-Step Bidirectional Relaying

In this paper, we present a low-complexity algorithm for the broadcast of three-step bidirectional relaying that decides which resources should be used for a network coding transmission, and which resources should be used for a conventional transmission. The algorithm requires a simple comparison operation for every transmission resource, and is independent from one resource to another thus enabling a parallel processing per transmission resource if desired. The comparison metric is based on information readily available in today's wireless networks, hence not requiring any additional overhead signalling. Simulation results show that the proposed algorithm provides comparable gains to the higher-complexity heuristic-based approaches found in the literature, rendering it a good candidate for practical implementation purposes.