Effects of Channel Aging in Massive MIMO Systems

TL;DR

This paper investigates how channel aging impacts massive MIMO system performance, analyzing capacity loss due to channel variation and proposing channel prediction to mitigate aging effects.

Contribution

It provides an analytical characterization of channel aging effects in massive MIMO and introduces channel prediction as a method to counteract these effects.

Findings

Channel aging causes capacity loss in massive MIMO systems.

Massive MIMO remains effective despite some channel variation.

Channel prediction can partially mitigate aging effects.

Abstract

MIMO communication may provide high spectral efficiency through the deployment of a very large number of antenna elements at the base stations. The gains from massive MIMO communication come from the use of multi-user MIMO on the uplink and downlink, but with a large excess of antennas at the base station compared to the number of served users. Initial work on massive MIMO did not fully address several practical issues associated with its deployment. This paper considers the impact of channel aging on the performance of massive MIMO systems. The effects of channel variation are characterized as a function of different system parameters assuming a simple model for the channel time variations at the transmitter. Channel prediction is proposed to overcome channel aging effects. The analytical results on aging show how capacity is lost due to time variation in the channel. Numerical results in a multicell network show that massive MIMO works even with some channel variation and that channel prediction could partially overcome channel aging effects.