TransFusion: Generating Long, High Fidelity Time Series using Diffusion Models with Transformers
Md Fahim Sikder, Resmi Ramachandranpillai, Fredrik Heintz
TL;DR
TransFusion addresses the challenge of generating high-fidelity, long-sequence time-series by coupling a diffusion-based generative process with a Transformer encoder in the denoising network. The authors introduce two transformer-based evaluation metrics, Long-Sequence Discriminative Score (LDS) and Long-Sequence Predictive Score (LPS), along with standard metrics like Jensen-Shannon Divergence and coverage to assess fidelity, diversity, and predictive characteristics. Empirical results on four datasets show that TransFusion outperforms eight baselines across sequence lengths of $N=100$ and $N=384$, with ablations confirming that the diffusion+Transformer pairing is essential. The work demonstrates practical impact by enabling reliable long-sequence generation and providing robust evaluation tools, potentially benefiting synthetic data applications in finance, energy, and environmental domains.
Abstract
The generation of high-quality, long-sequenced time-series data is essential due to its wide range of applications. In the past, standalone Recurrent and Convolutional Neural Network-based Generative Adversarial Networks (GAN) were used to synthesize time-series data. However, they are inadequate for generating long sequences of time-series data due to limitations in the architecture. Furthermore, GANs are well known for their training instability and mode collapse problem. To address this, we propose TransFusion, a diffusion, and transformers-based generative model to generate high-quality long-sequence time-series data. We have stretched the sequence length to 384, and generated high-quality synthetic data. Also, we introduce two evaluation metrics to evaluate the quality of the synthetic data as well as its predictive characteristics. We evaluate TransFusion with a wide variety of visual and empirical metrics, and TransFusion outperforms the previous state-of-the-art by a significant margin.
