Theoretical Approaches to Compression under Modern Constraints

Elza Erkip

Classical source coding theory assumes long blocklengths, i.i.d. sources and a decoder whose only job is to reconstruct the data. Autonomous driving, the Internet of Things, distributed sensing and federated learning break these assumptions. Data must be sent under strict delay constraints, sources have memory, devices compress correlated data separately, and the receiver may need an inference as well as a reconstruction.

This project extends compression theory to these settings, with an emphasis on logarithmic loss, a distortion measure for probabilistic predictions that connects to the information bottleneck framework. For single-shot compression with joint inference and reconstruction, we bound the probability of excess distortion, with an easily computable achievability bound when reconstruction is measured by logarithmic loss. For the one-shot Wyner–Ziv problem, we derive upper and lower bounds on the entropy–distortion function of a uniform source with quantized or noisy side information. Further work studies stationary sources under logarithmic loss.

Source codingSingle-shot compressionLogarithmic lossWyner–Ziv codingInformation bottleneckSources with memory
Modern systems depart from classical source coding in four ways: single-shot operation, sources with memory, distributed side information and multiple decoding tasks.
Entropy needed at each distortion for one-shot compression of a uniform source when the decoder has correlated side information (K = 1/α = 32). The achievable curves sit close to the lower bound, and the bounds tighten at higher rates. Data from Ülger and Erkip, ISIT 2024.

Faculty

Elza Erkip

Students

Oğuzhan Kubilay Ülger