Location-Aware Pilot Allocation in Multi-Cell Multi-User Massive MIMO Networks

TL;DR

This paper introduces a low-complexity, location-aware pilot allocation algorithm for high-mobility massive MIMO networks that leverages LOS interference behavior to enhance spectral efficiency.

Contribution

It presents a novel pilot allocation method that accounts for user locations and LOS interference, improving efficiency over existing algorithms in high-mobility scenarios.

Findings

Up to 37.26% increase in sum spectral efficiency.

Improvement of up to 2.57 bits/sec/Hz for worst-case users.

Effective even with localization errors.

Abstract

We propose a location-aware pilot allocation algorithm for a massive multiple-input multiple-output (MIMO) network with high-mobility users, where the wireless channels are subject to Rician fading. Pilot allocation in massive MIMO is a hard combinatorial problem and depends on the locations of users. As such, it is highly complex to achieve the optimal pilot allocation in real-time for a network with high-mobility users. Against this background, we propose a low-complexity pilot allocation algorithm, which exploits the behavior of line-of-sight (LOS) interference among the users and allocate the same pilot sequence to the users with small LOS interference. Our examination demonstrates that our proposed algorithm significantly outperforms the existing algorithms, even with localization errors. Specifically, for the system considered in this work, our proposed algorithm provides up to 37.26% improvement in sum spectral efficiency (SE) and improves the sum SE of the worst interference-affected users by up to 2.57 bits/sec/Hz, as compared to the existing algorithms.