Uplink Coordinated Pilot Design for 1-bit Massive MIMO in Correlated Channel

TL;DR

This paper introduces a novel coordinated pilot design for 1-bit massive MIMO systems that improves channel estimation accuracy in correlated and multi-cell environments by leveraging fractional programming under low SNR assumptions.

Contribution

It develops an efficient pilot design method applicable to correlated channels and multi-cell systems, addressing intractable MSE optimization issues.

Findings

Outperforms conventional channel estimation methods

Effective in correlated and multi-cell environments

Improves MSE performance in low SNR regimes

Abstract

In this paper, we propose a coordinated pilot design method to minimize the channel estimation mean squared error (MSE) in 1-bit analog-to-digital converters (ADCs) massive multiple-input multiple-output (MIMO). Under the assumption that the well-known Bussgang linear minimum mean square error (BLMMSE) estimator is used for channel estimation, we first observe that the resulting MSE leads to an intractable optimization problem, as it involves the arcsin function and a complex multiple matrix ratio form. To resolve this, we derive the approximate MSE by assuming the low signal-to-noise ratio (SNR) regime, by which we develop an efficient coordinated pilot design based on a fractional programming technique. The proposed pilot design is distinguishable from the existing work in that it is applicable in general system environments, including correlated channel and multi-cell environments. We demonstrate that the proposed method outperforms the channel estimation accuracy performance compared to the conventional approaches.