On the Performance of Mismatched Data Detection in Large MIMO Systems

TL;DR

This paper explores how mismatched priors affect large MIMO system detection and introduces a tuned LAMA algorithm that balances performance and computational efficiency, achieving near-optimal results.

Contribution

It develops a tuned LAMA algorithm for mismatched priors in large MIMO systems, enhancing detection efficiency and performance analysis.

Findings

Carefully-selected priors enable simpler algorithms with near-optimal performance.

The proposed algorithms perform well with Gaussian and uniform priors.

Analysis recovers classical and recent results on MIMO detection.

Abstract

We investigate the performance of mismatched data detection in large multiple-input multiple-output (MIMO) systems, where the prior distribution of the transmit signal used in the data detector differs from the true prior. To minimize the performance loss caused by this prior mismatch, we include a tuning stage into our recently-proposed large MIMO approximate message passing (LAMA) algorithm, which allows us to develop mismatched LAMA algorithms with optimal as well as sub-optimal tuning. We show that carefully-selected priors often enable simpler and computationally more efficient algorithms compared to LAMA with the true prior while achieving near-optimal performance. A performance analysis of our algorithms for a Gaussian prior and a uniform prior within a hypercube covering the QAM constellation recovers classical and recent results on linear and non-linear MIMO data detection, respectively.