cs.ITApr 10, 2026

Diffusion Denoiser Achievable Analysis for Finite Blocklength Unsourced Random Access

Authors: Yuming Han, Yuxin Long

Organizations: Texas A&M University, Department of ECE, College Station, TX 77843, USA · University of Leeds, Institute for Transport Studies, Leeds, LS2 9JT, UK

Abstract

Polyanskiy proposed a framework for the unsourced multiple access channel (MAC) problem where users employ a common codebook in the finite blocklength regime. However, existing approaches handle channel noise before the joint decoder. In this work, we introduce a decoder compatible diffusion denoiser as a lightweight analysis within joint decoding. The score network is trained on samples drawn from the channel output distribution, making the method easy to integrate with existing code designs. In our theoretical analysis, we derive a diffusion-denoiser random-coding achievable bound that is strictly tighter. Simulations on existing decoders, including FASURA, MSUG-MRA and pilot-based method, show consistent performance gains with at least a 0.50.5 dB\mathrm{dB} improvement in required Eb/N0\mathrm{E_b/N_0} at a fixed error target.

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