WFTNet: Exploiting Global and Local Periodicity in Long-term Time Series Forecasting
Peiyuan Liu, Beiliang Wu, Naiqi Li, Tao Dai, Fengmao Lei, Jigang Bao, Yong Jiang, Shu-Tao Xia
TL;DR
WFTNet tackles long-term time series forecasting by jointly modeling global and local periodic structures. It integrates Fourier (global) and continuous wavelet transforms (local) within WFTBlocks, using a Time-Frequency Inception Block and a Periodicity-Weighted Coefficient (PWC) to adaptively balance the two views. The approach yields state-of-the-art results across diverse datasets and horizons, with ablations showing the value of PWC in adjusting to dataset periodicity. This work advances practical forecasting by providing a unified, frequency-aware framework that adapts to varying temporal patterns and non-stationarities, with code available for replication.
Abstract
Recent CNN and Transformer-based models tried to utilize frequency and periodicity information for long-term time series forecasting. However, most existing work is based on Fourier transform, which cannot capture fine-grained and local frequency structure. In this paper, we propose a Wavelet-Fourier Transform Network (WFTNet) for long-term time series forecasting. WFTNet utilizes both Fourier and wavelet transforms to extract comprehensive temporal-frequency information from the signal, where Fourier transform captures the global periodic patterns and wavelet transform captures the local ones. Furthermore, we introduce a Periodicity-Weighted Coefficient (PWC) to adaptively balance the importance of global and local frequency patterns. Extensive experiments on various time series datasets show that WFTNet consistently outperforms other state-of-the-art baseline. Code is available at https://github.com/Hank0626/WFTNet.
