Performance Scaling Law for Multi-Cell Multi-User Massive MIMO

TL;DR

This paper develops a comprehensive scaling law for multi-cell multi-user massive MIMO downlink systems, analyzing the effects of imperfect CSI, pilot contamination, and spatial correlation on system performance.

Contribution

It introduces a new asymptotic scaling law for SINR considering practical impairments and pilot contamination, extending existing theoretical frameworks.

Findings

Derived a sum-rate lower bound using deterministic properties of received signals.

Established the asymptotic scaling law of effective SINR with respect to network parameters.

Provided conditions for SINR to be asymptotically deterministic, including pilot contamination effects.

Abstract

This work provides a comprehensive scaling law based performance analysis for multi-cell multi-user massive multiple-input-multiple-output (MIMO) downlink systems. Imperfect channel state information (CSI), pilot contamination, and channel spatial correlation are all considered. First, a sum- rate lower bound is derived by exploiting the asymptotically deterministic property of the received signal power, while keeping the random nature of other components in the signal-to-interference-plus-noise-ratio (SINR) intact. Via a general scaling model on important network parameters, including the number of users, the channel training energy and the data transmission power, with respect to the number of base station antennas, the asymptotic scaling law of the effective SINR is obtained, which reveals quantitatively the tradeoff of the network parameters. More importantly, pilot contamination and pilot contamination elimination (PCE) are considered in the analytical framework. In addition, the applicability of the derived asymptotic scaling law in practical systems with large but finite antenna numbers are discussed. Finally, sufficient conditions on the parameter scalings for the SINR to be asymptotically deterministic in the sense of mean square convergence are provided, which covers existing results on such analysis as special cases and shows the effect of PCE explicitly.