Effective Probabilistic Time Series Forecasting with Fourier Adaptive Noise-Separated Diffusion
Xinyan Wang, Rui Dai, Kaikui Liu, Xiangxiang Chu

TL;DR
FALDA introduces a Fourier-based probabilistic framework for time series forecasting that reduces epistemic uncertainty and outperforms existing methods in accuracy and efficiency.
Contribution
The paper presents FALDA, a novel Fourier adaptive diffusion model with a lightweight denoiser, advancing probabilistic time series forecasting.
Findings
FALDA outperforms existing probabilistic forecasting methods on six benchmarks.
FALDA achieves up to 9% improvement over state-of-the-art point forecasting.
FALDA enhances computational efficiency without sacrificing accuracy.
Abstract
We propose the Fourier Adaptive Lite Diffusion Architecture (FALDA), a novel probabilistic framework for time series forecasting. First, we introduce the Diffusion Model for Residual Regression (DMRR) framework, which unifies diffusion-based probabilistic regression methods. Within this framework, FALDA leverages Fourier-based decomposition to incorporate a component-specific architecture, enabling tailored modeling of individual temporal components. A conditional diffusion model is utilized to estimate the future noise term, while our proposed lightweight denoiser, DEMA (Decomposition MLP with AdaLN), conditions on the historical noise term to enhance denoising performance. Through mathematical analysis and empirical validation, we demonstrate that FALDA effectively reduces epistemic uncertainty, allowing probabilistic learning to primarily focus on aleatoric uncertainty. Experiments…
Peer Reviews
Decision·Submitted to ICLR 2026
1. The paper is easy to follow and well written. 2. The visual examples are complete and clearly presented.
1. I don’t understand how the paper separates epistemic uncertainty and aleatoric uncertainty. Epistemic uncertainty comes from the model’s limited predictive capability, which should reside in the residuals component in line 250, but the authors do not explicitly model different types of uncertainty within the residuals. 2. To my knowledge, due to the inherent non-stationarity of time series data, the associated uncertainty often exhibits temporal shifts. However, the authors only use noise as
- **S1** The FALDA framework reduces epistemic uncertainty by explicitly modeling time series components through time-series-decomposition-based modeling. - **S2** The authors theoretically prove the equivalence between the DMRR (Diffusion Model with Residual Regression) scheme and CARD, strengthening the methodological foundation.
- **W1** The Fourier-based decomposition introduces two hyperparameters ($K_1$ and $K_2$). It appears that the selection of these hyperparameters varies across different datasets, which could potentially increase the practical deployment difficulty of the model. In new scenarios, determining optimal values for these hyperparameters is non-trivial, potentially limiting the model’s deployability. - **W2** It is difficult to ensure that the Fourier-based sequence decomposition can effectively ext
- **S1** The paper is well-motivated, with clear writing and presentation that makes the technical contributions accessible. - **S2** The paper propose a theoretical framework DMRR, which mathematically classifies the existing diffusion-based time-series forecasting methods. - **S3** As a plug-and-play method, FALDA shows broad applicability and can enhance existing forecasting methods.
- **W1** FALDA's Fourier decomposition process involves two key hyperparameters, K1 and K2. It appears that the selection of these hyperparameters varies across different datasets, which could potentially increase the practical deployment difficulty of the model. - **W2** Limited complexity experiments. The authors demonstrate the training and inference efficiency of FALDA in Appendix F.6, and Figure 6 shows its fast convergence property. However, this experiment is conducted only on the small-
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Taxonomy
TopicsForecasting Techniques and Applications · Traffic Prediction and Management Techniques · Stock Market Forecasting Methods
MethodsFocus · Diffusion
