Performance analysis for transmission of correlated sources over non-orthogonal MARCs

Non-orthogonal transmission is considered as one of the promising approaches to improve the throughput of current and future wireless communication networks. We focus on the transmission of correlated sources over a non-orthogonal multiple access relay channel (MARC), which consists of two sources, one relay, and one destination. For non-orthogonal transmission over such networks, only two time slots are required as compared to three time slots used in the conventional orthogonal MARC. At the relay node, physical-layer network coding technique is employed to decode the bit-wise exclusive OR (XOR) version of the sources' information sequences rather than decode their original individual information sequences. Subsequently, the relay re-encodes the decoded combined sequence and forwards it to the destination. The destination then exploits this sequence as a helper to recover the sources' original individual information sequences. We analyze the outage probability of the non-orthogonal MARC based on the theorem of multiple access channel (MAC) with a helper, which combines Slepian-Wolf compression rate region and MAC capacity region. Simulation results are provided to verify the accuracy of the theoretical analysis.