Performance Analysis of Optimum Zero-Forcing Beamforming with Greedy User Selection

TL;DR

This paper provides an exact performance analysis of zero-forcing beamforming with greedy user selection in downlink systems, deriving a compact joint probability density function for scheduled users' gains and validating results numerically.

Contribution

It introduces a precise analytical framework for the sum rate performance of zero-forcing beamforming with greedy user scheduling, including a novel derivation of the joint PDF of user gains.

Findings

Derived a compact joint PDF for user gains under the scheme.

Validated the analytical results with numerical simulations.

Provided insights into the sum rate performance with at most two users.

Abstract

In this letter, an exact performance analysis is presented on the sum rate of zero-forcing beamforming with a greedy user scheduling algorithm in a downlink system. Adopting water-filling power allocation, we derive a compact form for the joint probability density function of the scheduled users' squared subchannel gains when a transmitter with multiple antennas sends information to at most two scheduled users with each having a single antenna. The analysis is verified by numerical results.