Existing quantization-aware training often fails because it optimizes on fixed data while the deployed model generates its own prefixes, causing quantization errors to push the model into unseen states. OnlineQAT addresses this by first initializing a low-bit model via block-wise QAT and then performing on-policy distillation on the student's own generated responses. A frozen full-precision teacher provides a reverse-KL training signal at each visited prefix to correct these distributional shifts.
- Fixes accuracy loss when deploying LLMs compressed below four bits.
- Uses on-policy distillation to match the model's actual inference behavior.
- Frozen teacher applies reverse-KL signals to correct student prefix drift.
- Two-stage process: block-wise initialization followed by self-generated distillation.