Uplink Performance of Large Optimum-Combining Antenna Arrays in Power-Controlled Cellular Networks

TL;DR

This paper analyzes the uplink spectral efficiency of large antenna array cellular networks with MMSE processing, providing asymptotic approximations and showing that simple power control suffices when the number of antennas and mobiles is large.

Contribution

It introduces asymptotic approximations for spectral efficiency in large MIMO cellular systems and demonstrates that simple, independent power control is effective.

Findings

Spectral efficiencies are well approximated asymptotically.

Correlations between mobile powers have negligible impact in large systems.

Simple power control schemes are sufficient for large antenna and mobile counts.

Abstract

The uplink of interference-limited cellular networks with base stations that have large numbers of antennas and use linear Minimum-Mean-Square Error (MMSE) processing with power control is analyzed. Simple approximations, which are exact in an asymptotic sense, are provided for the spectral efficiencies (b/s/Hz) of links in these systems. It is also found that when the number of base-station antennas is moderately large, and the number of mobiles in the entire network is large, correlations between the transmit powers of mobiles within a given cell do not significantly influence the spectral efficiency of the system. As a result, mobiles can perform simple power control (e.g. fractional power control) that does not depend on other users in the network, reducing system complexity and improving the analytical tractability of such systems.