On the Capacity Region and the Generalized Degrees of Freedom Region for the MIMO Interference Channel with Feedback

TL;DR

This paper characterizes the capacity and generalized degrees of freedom regions of two-user MIMO interference channels with feedback, showing they are within a constant number of bits of the true regions, regardless of channel matrices.

Contribution

It provides the first constant-gap capacity characterization for MIMO interference channels with feedback and relates the capacity regions of reciprocal channels.

Findings

Capacity region is within a constant number of bits with feedback.

Reciprocal channels have capacity regions within a constant number of bits.

Generalized degrees of freedom region is explicitly characterized.

Abstract

In this paper, we study the effect of feedback on two-user MIMO interference channels. The capacity region of MIMO interference channels with feedback is characterized within a constant number of bits, where this constant is independent of the channel matrices. Further, it is shown that the capacity region of a MIMO interference channel with feedback and its reciprocal interference channel are within a constant number of bits. Finally, the generalized degrees of freedom region for the MIMO interference channel with feedback is characterized.