Two-Way Source-Channel Coding

TL;DR

This paper introduces an adaptive joint source-channel coding scheme for two-way channels that reduces distortion by coupling terminal operations and exploiting source correlation, improving upon existing methods.

Contribution

It presents a novel adaptive JSCC scheme for two-way channels that enhances performance and derives bounds, with some cases where separate coding is optimal.

Findings

The adaptive JSCC scheme outperforms existing methods.

Outer bounds and complete theorems are established for certain settings.

In some cases, separate source-channel coding achieves optimal performance.

Abstract

We propose an adaptive lossy joint source-channel coding (JSCC) scheme for sending correlated sources over two-terminal discrete-memoryless two-way channels (DM-TWCs). The main idea is to couple the independent operations of the terminals via an adaptive coding mechanism, which can mitigate cross-interference resulting from simultaneous channel transmissions and concurrently exploit the sources' correlation to reduce the end-to-end reconstruction distortions. Our adaptive JSCC scheme not only subsumes existing lossy coding methods for two-way simultaneous communication but also improves their performance. Furthermore, we derive outer bounds for our two-way lossy transmission problem and establish complete JSCC theorems in some special settings. In these special cases, a non-adaptive separate source-channel coding (SSCC) scheme achieves the optimal performance, thus simplifying the design of the source-channel communication system.