On the Optimality of Beamforming for Multi-User MISO Interference Channels with Single-User Detection

TL;DR

This paper demonstrates that in multi-user MISO interference channels with single-user detection, optimal beamforming can achieve all boundary points of the achievable rate region by transforming the non-convex optimization problems into convex ones.

Contribution

The paper shows that beamforming is optimal for achieving the boundary of the rate region in multi-user MISO interference channels with single-user detection, through problem transformation.

Findings

Beamforming achieves all boundary points of the rate region.

Non-convex problems are converted into convex problems.

Optimality of beamforming under single-user detection.

Abstract

For a multi-user interference channel with multi-antenna transmitters and single-antenna receivers, by restricting each receiver to a single-user detector, computing the largest achievable rate region amounts to solving a family of non-convex optimization problems. Recognizing the intrinsic connection between the signal power at the intended receiver and the interference power at the unintended receiver, the original family of non-convex optimization problems is converted into a new family of convex optimization problems. It is shown that, for such interference channels with each receiver implementing single-user detection, transmitter beamforming can achieve all boundary points of the achievable rate region.