On the Sum-Capacity With Successive Decoding in Interference Channels
In this paper, the authors investigate the sum-capacity of the two-user Gaussian interference channel with Gaussian superposition coding and successive decoding. They first examine an approximate deterministic formulation of the problem, and introduce the complementarity conditions that capture the use of Gaussian coding and successive decoding. In the deterministic channel problem, they show that the constrained sum-capacity oscillates as a function of the cross link gain parameters between the information theoretic sum-capacity and the sum-capacity with interference treated as noise. Furthermore, they show that if the number of messages of either user is fewer than the minimum number required to achieve the constrained sum-capacity, the maximum achievable sum-rate drops to that with interference treated as noise.