On the Capacity of Non-Coherent Network Coding

Date Added: Nov 2010
Format: PDF

The authors consider the problem of multicasting information from a source to a set of receivers over a network where intermediate network nodes perform randomized network coding operations on the source packets. They propose a channel model for the non-coherent network coding introduced by Koetter and Kschischang, that captures the essence of such a network operation, and calculate the capacity as a function of network parameters. They prove that use of subspace coding is optimal, and show that, in some cases, the capacity-achieving distribution uses subspaces of several dimensions, where the employed dimensions depend on the packet length.