Attention-Aided MMSE for OFDM Channel Estimation: Learning Linear Filters with Attention

Fuente: arXiv
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Main Authors: Ha, TaeJun, Jung, Chaehyun, Kim, Hyeonuk, Park, Jeongwoo, Park, Jeonghun
Format: Preprint
Published: 2025
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author Ha, TaeJun
Jung, Chaehyun
Kim, Hyeonuk
Park, Jeongwoo
Park, Jeonghun
author_facet Ha, TaeJun
Jung, Chaehyun
Kim, Hyeonuk
Park, Jeongwoo
Park, Jeonghun
contents In orthogonal frequency division multiplexing (OFDM), accurate channel estimation is crucial. Classical signal processing-based approaches, such as linear minimum mean-squared error (LMMSE) estimation, often require second-order statistics that are difficult to obtain in practice. Recent deep neural network (DNN)-based methods have been introduced to address this; yet they often suffer from high inference complexity. This paper proposes an Attention-aided MMSE (A-MMSE), a model-based DNN framework that learns the linear MMSE filter via the Attention Transformer. Once trained, the A-MMSE performs channel estimation through a single linear operation, eliminating nonlinear activations during inference and thus reducing computational complexity. To improve the learning efficiency of the A-MMSE, we develop a two-stage Attention encoder that captures the frequency and temporal correlation structure of OFDM channels. We also introduce a rank-adaptive extension that enables a flexible performance-complexity trade-off. Numerical simulations show that the proposed A-MMSE consistently outperforms other baseline methods in terms of normalized MSE across a wide range of signal-to-noise ratio (SNR) conditions. In particular, the A-MMSE and its rank-adaptive extension provide an improved performance-complexity trade-off, providing a powerful and highly efficient solution for practical channel estimation.
format Preprint
id arxiv_https___arxiv_org_abs_2506_00452
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Attention-Aided MMSE for OFDM Channel Estimation: Learning Linear Filters with Attention
Ha, TaeJun
Jung, Chaehyun
Kim, Hyeonuk
Park, Jeongwoo
Park, Jeonghun
Signal Processing
Artificial Intelligence
Machine Learning
In orthogonal frequency division multiplexing (OFDM), accurate channel estimation is crucial. Classical signal processing-based approaches, such as linear minimum mean-squared error (LMMSE) estimation, often require second-order statistics that are difficult to obtain in practice. Recent deep neural network (DNN)-based methods have been introduced to address this; yet they often suffer from high inference complexity. This paper proposes an Attention-aided MMSE (A-MMSE), a model-based DNN framework that learns the linear MMSE filter via the Attention Transformer. Once trained, the A-MMSE performs channel estimation through a single linear operation, eliminating nonlinear activations during inference and thus reducing computational complexity. To improve the learning efficiency of the A-MMSE, we develop a two-stage Attention encoder that captures the frequency and temporal correlation structure of OFDM channels. We also introduce a rank-adaptive extension that enables a flexible performance-complexity trade-off. Numerical simulations show that the proposed A-MMSE consistently outperforms other baseline methods in terms of normalized MSE across a wide range of signal-to-noise ratio (SNR) conditions. In particular, the A-MMSE and its rank-adaptive extension provide an improved performance-complexity trade-off, providing a powerful and highly efficient solution for practical channel estimation.
title Attention-Aided MMSE for OFDM Channel Estimation: Learning Linear Filters with Attention
topic Signal Processing
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2506.00452