Slepian-Wolf Coding Over Cooperative Relay Networks

TL;DR

This paper develops a new coding scheme for multicasting correlated sources over cooperative relay networks, providing both necessary and sufficient conditions for reliable transmission, and demonstrating its effectiveness in various network models.

Contribution

It introduces a joint source-Wyner-Ziv encoding and sliding window decoding scheme with a novel geometrical approach, advancing the understanding of multicasting in cooperative relay networks.

Findings

Achieves operational separation between source and channel coding.

Provides necessary and sufficient conditions in specific network models.

Demonstrates reliable transmission within a constant gap of the cut-set bound.

Abstract

This paper deals with the problem of multicasting a set of discrete memoryless correlated sources (DMCS) over a cooperative relay network. Necessary conditions with cut-set interpretation are presented. A \emph{Joint source-Wyner-Ziv encoding/sliding window decoding} scheme is proposed, in which decoding at each receiver is done with respect to an ordered partition of other nodes. For each ordered partition a set of feasibility constraints is derived. Then, utilizing the sub-modular property of the entropy function and a novel geometrical approach, the results of different ordered partitions are consolidated, which lead to sufficient conditions for our problem. The proposed scheme achieves operational separation between source coding and channel coding. It is shown that sufficient conditions are indeed necessary conditions in two special cooperative networks, namely, Aref network and finite-field deterministic network. Also, in Gaussian cooperative networks, it is shown that reliable transmission of all DMCS whose Slepian-Wolf region intersects the cut-set bound region within a constant number of bits, is feasible. In particular, all results of the paper are specialized to obtain an achievable rate region for cooperative relay networks which includes relay networks and two-way relay networks.