Outage Probability and Outage-Based Robust Beamforming for MIMO Interference Channels with Imperfect Channel State Information

TL;DR

This paper derives closed-form outage probability expressions for MIMO interference channels with imperfect CSI, analyzes their asymptotic behavior, and proposes an iterative beamforming algorithm to maximize sum outage rate, outperforming conventional methods.

Contribution

It provides the first closed-form outage probability expressions under Gaussian CSI errors and introduces a novel beamforming algorithm optimized for outage performance.

Findings

Outage probability decreases exponentially with CSI quality.

The proposed beamforming algorithm improves sum outage rate.

Numerical results outperform conventional interference alignment.

Abstract

In this paper, the outage probability and outage-based beam design for multiple-input multiple-output (MIMO) interference channels are considered. First, closed-form expressions for the outage probability in MIMO interference channels are derived under the assumption of Gaussian-distributed channel state information (CSI) error, and the asymptotic behavior of the outage probability as a function of several system parameters is examined by using the Chernoff bound. It is shown that the outage probability decreases exponentially with respect to the quality of CSI measured by the inverse of the mean square error of CSI. Second, based on the derived outage probability expressions, an iterative beam design algorithm for maximizing the sum outage rate is proposed. Numerical results show that the proposed beam design algorithm yields better sum outage rate performance than conventional algorithms such as interference alignment developed under the assumption of perfect CSI.