Coherent and Noncoherent Detection in Dense Arrays: Can We Ignore Mutual Coupling?

TL;DR

This paper examines how mutual coupling affects dense antenna array MIMO systems, revealing that noncoherent detection offers robustness at the cost of higher error rates, especially when the receiver ignores coupling effects.

Contribution

It provides a comparative analysis of coherent and noncoherent detection in dense arrays, highlighting the impact of mutual coupling and the robustness of noncoherent methods.

Findings

Coherent detection is more accurate but sensitive to coupling mismatches.

Noncoherent detection is more robust to mutual coupling model errors.

Ignoring mutual coupling can severely degrade coherent detection performance.

Abstract

This paper investigates the impact of mutual coupling on MIMO systems with densely deployed antennas. Leveraging multiport communication theory, we analyze both coherent and noncoherent detection approaches in a single-user uplink scenario where the receiver ignores mutual coupling effects. Simulation results indicate that while coherent detection is generally more accurate, it is highly sensitive to mismatches in the coupling model, leading to severe performance degradation when antennas are closely spaced, to the point of becoming unusable. Noncoherent detection, on the other hand, exhibits a higher error probability but is more robust to coupling model mismatches.