Scnet: spectral convolutional networks for multivariate time series classification

Abstract With the widespread application of time series data, the study of classification techniques has become an important topic. Although existing multivariate time series classification (MTSC) methods have made progress, they often rely on one-dimensional (1D) time series, which limits their ability to capture complex temporal dynamics and multiscale features. To address these challenges, a Spectral Convolutional Network (SCNet) is introduced in this work. SCNet effectively transforms 1D time series data into the frequency domain using an enhanced Discrete Fourier Transform (enhanced_DFT), revealing periodicity and key frequency components while reshaping the data into a two-dimensional (2D) time series for better representation. Furthermore, it uses a Spectral Energy Prioritization method to optimize frequency domain energy distribution and a multiscale convolutional module to capture features at different scales, improving the model’s ability to analyze short-term and long-term trends. To validate the effectiveness and superiority, we conducted extensive experiments on 10 sub-datasets from the well-known UEA dataset. The results show that our proposed SCNet achieved the highest average accuracy of 74.3%, which is 2.2% higher than the current state-of-the-art models, demonstrating its potential for practical application and efficiency in MTSC task.