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.