On the Diversity Gain Region for the Relay Assisted Interference Management

The present paper focuses on the interference management in a two-user Z-channel where one user is interference-limited while the other user is interference-free. The achievable diversity gain region (DGR) with interference forwarding by a full-duplex decode-and-forward (FD-DF) relay and successive interference cancellation (SIC) at the interference-limited destination is studied. The achievable DGR of the FD-DF relay is compared with that of the direct transmission scheme. The impact of the phase-noise in the self-interference cancellation circuit of the full-duplex relay and the impact of the number of blocks in the superposition block Markov (SPBM) encoding on the achievable DGR are studied. The direct transmission scheme with joint decoding at the interference-limited receiver is shown to perform well at the lower multiplexing gain region (MGR). If the multiplexing gain of the interference is high, then the interference forwarding by the DF relay does not help, and the direct transmission scheme with interference ignorant detection at the interference-limited receiver achieves better DGR. The FD-DF relay is shown to provide better DGR at only the moderate MGR.