Stein Variational Gradient Descent-based Detection For Random Access With Preambles In MTC

TL;DR

This paper introduces a novel preamble detection algorithm for massive machine-type communication that uses Stein variational gradient descent, significantly improving detection accuracy over traditional methods, especially in dense user scenarios.

Contribution

The paper proposes a new SVGD-based preamble detection method with momentum and bias correction, enhancing accuracy in grant-based random access for mMTC.

Findings

Outperforms MCMC-based approaches in detection accuracy

Effective in dense user scenarios

Improves preamble estimation with normalized SVGD

Abstract

Traditional preamble detection algorithms have low accuracy in the grant-based random access scheme in massive machine-type communication (mMTC). We present a novel preamble detection algorithm based on Stein variational gradient descent (SVGD) at the second step of the random access procedure. It efficiently leverages deterministic updates of particles for continuous inference. To further enhance the performance of the SVGD detector, especially in a dense user scenario, we propose a normalized SVGD detector with momentum. It utilizes the momentum and a bias correction term to reduce the preamble estimation errors during the gradient descent process. Simulation results show that the proposed algorithm performs better than Markov Chain Monte Carlo-based approaches in terms of detection accuracy.