Performance Analysis of Dual-User Macrodiversity MIMO Systems with Linear Receivers in Flat Rayleigh Fading

TL;DR

This paper derives analytical expressions for the performance of linear MMSE and ZF receivers in dual-user macrodiversity MIMO systems over Rayleigh fading channels, addressing the challenge of unequal SNRs across widely separated antennas.

Contribution

It provides the first closed-form expressions for SINR and SNR distributions in macrodiversity MIMO systems with arbitrary receive antennas and unequal SNRs, specifically for the two-user case.

Findings

Closed-form pdf and cdf for SINR and SNR of MMSE and ZF receivers.

Verification of analytical results through Monte Carlo simulations.

High SNR approximations enabling system performance evaluation.

Abstract

The performance of linear receivers in the presence of co-channel interference in Rayleigh channels is a fundamental problem in wireless communications. Performance evaluation for these systems is well-known for receive arrays where the antennas are close enough to experience equal average SNRs from a source. In contrast, almost no analytical results are available for macrodiversity systems where both the sources and receive antennas are widely separated. Here, receive antennas experience unequal average SNRs from a source and a single receive antenna receives a different average SNR from each source. Although this is an extremely difficult problem, progress is possible for the two-user scenario. In this paper, we derive closed form results for the probability density function (pdf) and cumulative distribution function (cdf) of the output signal to interference plus noise ratio (SINR) and signal to noise ratio (SNR) of minimum mean squared error (MMSE) and zero forcing (ZF) receivers in independent Rayleigh channels with arbitrary numbers of receive antennas. The results are verified by Monte Carlo simulations and high SNR approximations are also derived. The results enable further system analysis such as the evaluation of outage probability, bit error rate (BER) and capacity.