TEMPO: Time Series Understanding via Discrete Tokenization

Abstract:Time-series interpretation often requires both numerical observations and textual context. Integrating these inputs into a pretrained language model raises a representation question: how should a signal enter the model's token sequence? We present TEMPO, which extends an LLM's vocabulary with discrete codes from a context-aware Transformer tokenizer using finite scalar quantization. A frozen tokenizer maps four-step patches to a 625-code vocabulary; signal tokens, scale statistics, and text are then processed by the LLM's existing self-attention layers. Adaptation updates the new token embeddings and DoRA adapters. With a Qwen3-4B backbone and task-specific fine-tuning, TEMPO achieves macro-F1 scores of 89.0% on activity recognition, 85.0% on sleep staging, and 86.0% on bearing-fault diagnosis. Time-series question answering and qualitative bearing-diagnosis examples further illustrate how this interface combines signal representations with textual context. Together, these results demonstrate the utility of discrete vocabulary extension for time-series understanding.

9 pages, 2 figures. Presented at the 2nd ICML Workshop on Foundation Models for Structured Data (FMSD), 2026

Computation and Language (cs.CL)

arXiv:2611.04482 [cs.CL]

(or arXiv:2611.04482v1 [cs.CL] for this version)

https://doi.org/10.48550/arXiv.2611.04482 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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