Short Message Noisy Network Coding with Rate Splitting

Short message noisy network coding with rate splitting (SNNC-RS) encoding strategy is presented. It has been shown by Hou and Kramer that mixed cooperative strategies in which relays in favorable positions perform decode-and-forward (DF) and the rest of the relays perform short message noisy network coding (SNNC) can outperform noisy network coding (NNC). Our proposed strategy further improves the rate performance of such mixed SNNC-DF cooperative strategy. In the proposed scheme, superposition coding is incorporated into the SNNC encoding in order to facilitate partial interference cancellation at DF relays, thereby increasing the overall rate. To demonstrate gains of the proposed SNNC-RS strategy, the achievable rate is analyzed for the discrete memoryless two-relay network with one DF relay and one SNNC-RS relay and compared to the case without rate-splitting. The obtained rate is evaluated in the Gaussian two-relay network and gains over the rate achieved without rate splitting are demonstrated.