Leveraging von Mises Message-Passing for Massive MIMO Detection

2026-07-18

AI Summary

This work addresses the impractical computational complexity of optimal detectors, such as maximum a posteriori (MAP), in large-scale MIMO systems under PSK modulation, where complexity grows exponentially with the modulation order. To overcome this limitation, the authors propose a novel belief propagation detector grounded in directional statistics, which introduces the von Mises distribution into the message-passing framework for the first time. By continuously relaxing PSK symbols onto the unit circle and parameterizing messages accordingly, the method achieves a sparse representation whose complexity is independent of the modulation order. The proposed detector significantly reduces computational overhead, accommodates imperfect channel state information, and demonstrates superior performance over Gaussian approximation-based detection algorithms across various PSK modulations and channel conditions.

Abstract

Detection in massive multiple input multiple output (mMIMO) systems suffers from exponential complexity while using optimal decoders like maximum a posteriori (MAP). We propose a belief propagation-based detector based on directional statistics, applicable to mMIMO systems relying on PSK modulations. Thanks to a continuous relaxation of the PSK modulation to the unit circle, and to the use of von Mises parametric representations of the messages to obtain sparse representations of the (generally infinite dimensional) messages, the proposed method allows for approximate detection with a low complexity which does not depend on the PSK modulation order. Extensions of the algorithm to imperfect channel realizations are also present. We quantify the performance and complexity of the proposed approach and compare it with detection algorithms based on Gaussian approximation.

Problem

• massive MIMO
• detection
• exponential complexity
• MAP decoding
• PSK modulation

Innovation

• von Mises distribution
• belief propagation
• massive MIMO detection
• directional statistics
• PSK modulation