On the sum-capacity of the linear deterministic interference channel with partial feedback

The linear deterministic interference channel (LD-IC) with partial feedback is considered. Partial feedback for the LD-IC models a scenario in which the top l most-significant-bits of the channel output of receiver j are received as feedback at transmitter j, for j = 1, 2. The rationale for studying the LD-IC with partial feedback comes from the fact that it is a good approximation to the Gaussian interference channel with output feedback corrupted by additive white Gaussian noise (commonly referred to as noisy feedback). The main contribution of this paper is a characterization of the sum-capacity of the symmetric LD-IC with partial feedback. The differences between the models of partial feedback and rate-limited feedback are emphasized and highlighted by comparing the corresponding sum-capacities, which are shown to differ in general.