Statistical Analysis of Downlink Zero-Forcing Beamforming

TL;DR

This paper provides a comprehensive statistical analysis of downlink zero-forcing beamforming in multi-cell networks, focusing on both mean and variance of signal and interference powers, and introduces practical outage calculations.

Contribution

It offers the first complete variance analysis of ZF-BF signal and interference powers, with closed-form expressions and practical outage estimation methods.

Findings

Closed-form expressions for mean and variance of signal and interference powers.

Demonstrated the importance of variance in ZF-BF performance analysis.

Analytical outage probability calculations using gamma or lognormal interference models.

Abstract

We analyze the mean and the variance of the useful signal and interference powers in a multi-cell network using zero-forcing beamforming (ZF-BF) with two beamformer normalization approaches. While the mean has been the main focus in earlier studies on ZF-BF, analysis of the variance has not been tackled. Our analysis provides a complete statistical study, sheds light on the importance of the variance by deriving closed-form expressions for the signals' two moments, and provides a practical use for these expressions; we use the gamma or lognormal distribution for the interference power to analytically calculate the outage.