Capacity Results for Binary Fading Interference Channels with Delayed CSIT

TL;DR

This paper characterizes the capacity region of two-user binary fading interference channels with delayed CSIT, introducing novel coding strategies and extending results to feedback and non-homogeneous scenarios.

Contribution

It provides the first capacity characterization for such channels with delayed CSIT and develops new coding schemes exploiting outdated information.

Findings

Capacity region characterized under homogeneous assumptions.

Novel coding opportunities created by outdated CSIT.

Extended results with output feedback and non-homogeneous channels.

Abstract

To study the effect of lack of up-to-date channel state information at the transmitters (CSIT), we consider two-user binary fading interference channels with Delayed-CSIT. We characterize the capacity region for such channels under homogeneous assumption where channel gains have identical and independent distributions across time and space, eliminating the possibility of exploiting time/space correlation. We introduce and discuss several novel coding opportunities created by outdated CSIT that can enlarge the achievable rate region. The capacity-achieving scheme relies on accurate combination, concatenation, and merging of these opportunities, depending on the channel statistics. The outer-bounds are based on an extremal inequality we develop for a binary broadcast channel with Delayed-CSIT. We further extend the results and characterize the capacity region when output feedback links are available from the receivers to the transmitters in addition to the delayed knowledge of the channel state information. We also discuss the extension of our results to the non-homogeneous setting.