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
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 0.5dB improvement in required Eb/N0 at a fixed error target.
Figures & tables
Figure 1: The required energy per bit to achieve ϵ=0.001 as a function of the number of active users for Theorem 1 and different achievable schemes.
Figure 2: The bounds on the probability of error ϵ as a function of Eb/N0 for Theorem 1 and different achievable schemes.
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Chengwei Zhang, Yifan Du, Siyu Liao
The School of Integrated Circuits Sun Yat-sen University Shenzhen, China
We present the first neural probabilistic amplitude shaping that outperforms existing methods while accounting for all implementation losses, using a block-less, easily implementable sequential autoregressive encoder compatible with arithmetic distribution matching, yielding reduced rate loss and higher achievable information rates.
Mohammad Taha Askari, Lutz Lampe, Amirhossein Ghazisaeidi
Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada · Nokia Bell Labs, 12 rue Jean Bart, 91300 Massy, France
Error-correcting codes enable reliable communication, yet practical soft decoding remains challenging across code families and block lengths. We propose SB-ECC, a score-based decoder that casts decoding as continuous-time denoising. A neural denoiser defines a probability-flow ordinary differential equation (ODE) that iteratively updates the noisy channel observation toward a valid codeword, guided by parity constraints. The model is trained across noise levels without time/SNR conditioning, enabling inference without SNR estimation and supporting a direct latency accuracy trade off controlled by the ODE solver budget. We use the raw signed channel observation as input for learning a continuous denoising field. Across 42 code/SNR settings, SB-ECC achieves the best BER in 39/42 entries, with an average SNR gain of 0.17dB and a maximum gain of 0.46dB over the strongest competing baseline, we showed that swapping the solver from Euler to DPM preserves -ln(BER) while reducing end-to-end decoding time by 8.86% on average (up to 12.82%).
Alon Helvits, Eliya Nachmani
School of Electrical and Computer Engineering (ECE), Ben Gurion University, Beer Sheva, Israel.