Equivalence perspectives in communication, source-channel connections and universal source-channel separation

TL;DR

This paper introduces a novel operational approach to understanding source-channel coding relationships, avoiding mutual information calculations, and proves a universal separation theorem for rate-distortion in compound channels.

Contribution

It presents a new reduction-based method that bypasses mutual information computations and establishes a universal source-channel separation theorem.

Findings

Operational reduction approach to source-channel coding

Universal separation theorem for rate-distortion in compound channels

Avoidance of mutual information calculations in proofs

Abstract

An operational perspective is used to understand the relationship between source and channel coding. This is based on a direct reduction of one problem to another that uses random coding (and hence common randomness) but unlike all prior work, does not involve any functional computations, in particular, no mutual-information computations. This result is then used to prove a universal source-channel separation theorem in the rate-distortion context where universality is in the sense of a compound ``general channel.''