Linear Network Coding for Two-Unicast-$Z$ Networks: A Commutative Algebraic Perspective and Fundamental Limits
Abstract
We consider a two-unicast- network over a directed acyclic graph of unit capacitated edges; the two-unicast- network is a special case of two-unicast networks where one of the destinations has apriori side information of the unwanted (interfering) message. In this paper, we settle open questions on the limits of network coding for two-unicast- networks by showing that the generalized network sharing bound is not tight, vector linear codes outperform scalar linear codes, and non-linear codes outperform linear codes in general. We also develop a commutative algebraic approach to deriving linear network coding achievability results, and demonstrate our approach by providing an alternate proof to the previous results of C. Wang et. al., I. Wang et. al. and Shenvi et. al. regarding feasibility of rate in the network.
Keywords
Cite
@article{arxiv.1705.02704,
title = {Linear Network Coding for Two-Unicast-$Z$ Networks: A Commutative Algebraic Perspective and Fundamental Limits},
author = {Mohammad Fahim and Viveck Cadambe},
journal= {arXiv preprint arXiv:1705.02704},
year = {2018}
}
Comments
A short version of this paper is published in the Proceedings of The IEEE International Symposium on Information Theory (ISIT), June 2017