Non-Identical Diffusion Models in MIMO-OFDM Channel Generation

Fuente: arXiv
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Auteurs principaux: Yang, Yuzhi, Alhussein, Omar, Debbah, Mérouane
Format: Preprint
Publié: 2025
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author Yang, Yuzhi
Alhussein, Omar
Debbah, Mérouane
author_facet Yang, Yuzhi
Alhussein, Omar
Debbah, Mérouane
contents We propose a novel diffusion model, termed the non-identical diffusion model, and investigate its application to wireless orthogonal frequency division multiplexing (OFDM) channel generation. Unlike the standard diffusion model that uses a scalar-valued time index to represent the global noise level, we extend this notion to an element-wise time indicator to capture local error variations more accurately. Non-identical diffusion enables us to characterize the reliability of each element (e.g., subcarriers in OFDM) within the noisy input, leading to improved generation results when the initialization is biased. Specifically, we focus on the recovery of wireless multi-input multi-output (MIMO) OFDM channel matrices, where the initial channel estimates exhibit highly uneven reliability across elements due to the pilot scheme. Conventional time embeddings, which assume uniform noise progression, fail to capture such variability across pilot schemes and noise levels. We introduce a matrix that matches the input size to control element-wise noise progression. Following a similar diffusion procedure to existing methods, we show the correctness and effectiveness of the proposed non-identical diffusion scheme both theoretically and numerically. For MIMO-OFDM channel generation, we propose a dimension-wise time embedding strategy. We also develop and evaluate multiple training and generation methods and compare them through numerical experiments.
format Preprint
id arxiv_https___arxiv_org_abs_2509_01641
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Non-Identical Diffusion Models in MIMO-OFDM Channel Generation
Yang, Yuzhi
Alhussein, Omar
Debbah, Mérouane
Signal Processing
Artificial Intelligence
Machine Learning
We propose a novel diffusion model, termed the non-identical diffusion model, and investigate its application to wireless orthogonal frequency division multiplexing (OFDM) channel generation. Unlike the standard diffusion model that uses a scalar-valued time index to represent the global noise level, we extend this notion to an element-wise time indicator to capture local error variations more accurately. Non-identical diffusion enables us to characterize the reliability of each element (e.g., subcarriers in OFDM) within the noisy input, leading to improved generation results when the initialization is biased. Specifically, we focus on the recovery of wireless multi-input multi-output (MIMO) OFDM channel matrices, where the initial channel estimates exhibit highly uneven reliability across elements due to the pilot scheme. Conventional time embeddings, which assume uniform noise progression, fail to capture such variability across pilot schemes and noise levels. We introduce a matrix that matches the input size to control element-wise noise progression. Following a similar diffusion procedure to existing methods, we show the correctness and effectiveness of the proposed non-identical diffusion scheme both theoretically and numerically. For MIMO-OFDM channel generation, we propose a dimension-wise time embedding strategy. We also develop and evaluate multiple training and generation methods and compare them through numerical experiments.
title Non-Identical Diffusion Models in MIMO-OFDM Channel Generation
topic Signal Processing
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2509.01641