Performance Analysis of ZF Receivers with Imperfect CSI for Uplink Massive MIMO Systems

TL;DR

This paper analyzes the uplink performance of massive MIMO systems with zero-forcing receivers under imperfect CSI, deriving exact and bound expressions for key performance metrics and validating them numerically.

Contribution

It provides exact analytical expressions for SINR, achievable rate, outage probability, and SER with imperfect CSI, including bounds for large antenna arrays, advancing understanding of practical massive MIMO performance.

Findings

Derived exact PDF of SINR under imperfect CSI

Established upper bounds for SER and achievable rate

Validated analytical results with numerical simulations

Abstract

We consider the uplink of massive multipleinput multiple-output systems in a multicell environment. Since the base station (BS) estimates the channel state information (CSI) using the pilot signals transmitted from the users, each BS will have imperfect CSI in practice. Assuming zero-forcing method to eliminate the multi-user interference, we derive the exact analytical expressions for the probability density function (PDF) of the signal-to-interference-plus-noise ratio (SINR), the corresponding achievable rate, the outage probability, and the symbol error rate (SER) when the BS has imperfect CSI. An upper bound of the SER is also derived for an arbitrary number of antennas at the BS. Moreover, we derive the upper bound of the achievable rate for the case where the number of antennas at the BS goes to infinity, and the analysis is verified by presenting numerical results.