User Load Analysis and Pilot Sequence Design for Multi-Cell Massive MIMO Networks

TL;DR

This paper introduces a new pilot sequence design algorithm for multi-cell massive MIMO networks that enhances user load capacity and SINR satisfaction, outperforming existing methods especially with finite antennas.

Contribution

The paper presents a novel pilot sequence algorithm based on generalized Welch bound equality, improving load region and SINR performance in multi-cell massive MIMO systems.

Findings

The proposed algorithm achieves a larger load region.

It ensures SINR requirements are met with finite antennas.

It outperforms existing designs in load and SINR metrics.

Abstract

We propose a novel algorithm to design user load-achieving pilot sequences that mitigate pilot contamination in multi-cell massive multiple-input multiple-output (MIMO) networks. To this end, we first derive expressions for the user load and the load region of the network considering both small-scale and large-scale propagation effects. We then develop the pilot sequence algorithm for multi-cell massive MIMO networks as per the rules of generalized Welch bound equality design. Notably, we find that our algorithm and the corresponding downlink power allocation ensure that the user load is achieved when the signal-to-interference-plus-noise ratio (SINR) requirements for the users lie within the load region. Furthermore, we demonstrate the performance advantage of our proposed design relative to the existing designs, in terms of a larger load region and a higher maximum permitted SINR. Finally, we show that our proposed design can satisfy the pre-defined SINR requirements for users with a finite number of antennas at the base station (BS), while the existing designs cannot satisfy the same requirements even with an infinite number of antennas at the BS.