On Asymmetric Interference Channels with Cooperating Receivers

This paper studies a model for communications in wireless networks supported by designated cooperation links. In particular, a 2-user Gaussian one-sided interference channel with two rate-limited and orthogonal communication links between the receivers is considered. A communication protocol for the channel is proposed, which combines rate-splitting and superposition encoding techniques with the conventional decode-forward and compress-forward strategies. It is shown that a careful design of codebooks and coding scheme, which is obtained from intuition based on superposition coding, can greatly reduce the complexity of the strategy. Analytical and numerical results show that the proposed scheme, although not universally optimal, can achieve the capacity region or sum capacity exactly or asymptotically in certain scenarios. Various limits of sum capacity gain due to cooperation are also discussed.