🤖 AI Summary
This work addresses the challenge of jointly modeling periodic patterns and residual dynamics in long-term multivariate time series forecasting. To this end, it proposes a decoupled yet complementary modeling paradigm: periodic components are captured through a learnable recurrent module combined with channel-wise nonlinear MLPs, while residual components are represented by extracting frequency-domain features via a learnable stationary wavelet transform (LSWT). These residuals are further processed using a channel-mixing encoder and a two-level non-overlapping hierarchical patch mechanism to effectively capture multiscale temporal dynamics. Evaluated on standard multivariate time series benchmarks, the proposed method achieves state-of-the-art or competitive performance, significantly improving long-horizon prediction accuracy.
📝 Abstract
In long-term multivariate time series forecasting, effectively capturing both periodic patterns and residual dynamics is essential. To address this within standard deep learning benchmark settings, we propose the Hierarchical Patching Mixer (HPMixer), which models periodicity and residuals in a decoupled yet complementary manner. The periodic component utilizes a learnable cycle module [7] enhanced with a nonlinear channel-wise MLP for greater expressiveness. The residual component is processed through a Learnable Stationary Wavelet Transform (LSWT) to extract stable, shift-invariant frequency-domain representations. Subsequently, a channel-mixing encoder models explicit inter-channel dependencies, while a two-level non-overlapping hierarchical patching mechanism captures coarse- and fine-scale residual variations. By integrating decoupled periodicity modeling with structured, multi-scale residual learning, HPMixer provides an effective framework. Extensive experiments on standard multivariate benchmarks demonstrate that HPMixer achieves competitive or state-of-the-art performance compared to recent baselines.