ORIGINAL RESEARCH article

Front. Appl. Math. Stat.

Sec. Mathematics of Computation and Data Science

Volume 11 - 2025 | doi: 10.3389/fams.2025.1600136

Fourier-Mixed Window Attention for Efficient and Robust Long Sequence Time-Series Forecasting

Provisionally accepted
  • University of California, Irvine, Irvine, United States

The final, formatted version of the article will be published soon.

We study a fast local-global window-based attention method to accelerate Informer for long sequence time-series forecasting (LSTF) in a robust manner. While window attention being local is a considerable computational saving, it lacks the ability to capture global token information which is compensated by a subsequent Fourier transform block. Our method, named FWin, does not rely on query sparsity hypothesis and an empirical approximation underlying the ProbSparse attention of Informer. Experiments on univariate and multivariate datasets show that FWin transformers improve the overall prediction accuracies of Informer while accelerating its inference speeds by 1.6 to 2 times. On strongly non-stationary data (power grid and dengue disease data), FWin outperforms Informer and recent SOTAs thereby demonstrating its superior robustness. We give mathematical definition of FWin attention, and prove its equivalency to the canonical full attention under the block diagonal invertibility (BDI) condition of the attention matrix. The BDI is verified to hold with high probability on benchmark datasets experimentally.

Keywords: window attention, Fourier mixing, global attention approximation, Fast inference, time series

Received: 25 Mar 2025; Accepted: 18 Apr 2025.

Copyright: © 2025 Tran and Xin. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Nhat Thanh Tran, University of California, Irvine, Irvine, United States

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