Network-Coded Interference Alignment in K-Pair Bidirectional Relaying Channels

In this paper, we propose a distributed interference alignment which employs physical-layer network coding and superposition coding for successive-cancelling multiuser detection (MUD) receivers in K-pair bidirectional relaying networks. The proposed scheme enables the transmitter to align only partial interference while strong interference is cancelled by MUD, and the transmitter can have more degrees of freedom in controlling the filter designs. Simulation results demonstrate that our proposed scheme significantly improves sum-rate performance in multiuser bidirectional relaying systems.