FASURA: A Scheme for Quasi-Static Massive MIMO Unsourced Random Access Channels

TL;DR

This paper introduces FASURA, a novel coding scheme for massive MIMO unsourced random access channels that combines activity detection, iterative channel estimation, and SIC to outperform existing methods in high-user regimes.

Contribution

FASURA is a new scheme that integrates activity detection, iterative channel estimation, and SIC, achieving superior performance for over 100 active users in massive MIMO systems.

Findings

Outperforms state-of-the-art schemes for more than 100 active users

Reduces energy-per-bit for fixed error probability

Effective in quasi-static Rayleigh fading channels

Abstract

This article considers the massive MIMO unsourced random access problem on a quasi-static Rayleigh fading channel. Given a fixed message length and a prescribed number of channel uses, the objective is to construct a coding scheme that minimizes the energy-per-bit subject to a fixed probability of error. The proposed scheme differs from other state-of-the-art schemes in that it blends activity detection, single-user coding, pilot-aided and temporary decisions-aided iterative channel estimation and decoding, minimum-mean squared error (MMSE) estimation, and successive interference cancellation (SIC). We show that an appropriate combination of these ideas can substantially outperform state-of-the-art coding schemes when the number of active users is more than 100, making this the best performing scheme known for this regime.