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arXiv cs/0504014cs.ITmath.IT
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具有相关源的网络信息流

Network Information Flow with Correlated Sources

Joao Barros, Sergio D. Servetto

摘要:

在本文中,我们考虑了一个网络通信问题,其中多个相关的源必须提供给一个单一的数据收集器节点,在一个网络的噪声独立的点对点通道。我们证明了,当且仅当,对于网络节点的所有划分为两个子集S和S^c,使得sink总是在S^c中,我们有H(U_S| U_{S^c})< \sum_{i\in S,j\in S^c} C_{ij}。我们的主要发现是,在这种设置中,一般的源/通道分离定理成立,香农信息的行为作为一个经典的网络流,在性质上相同的管道中的水流。乍看起来,分离在我们所研究的这种相当普遍的网络环境中成立似乎令人惊讶。然而,仔细观察会发现,这样做的原因是我们的模型只允许节点对之间的独立点对点信道,而不是多路访问和/或广播信道,众所周知,分离是不成立的。这个“信息流”视图为我们的结果提供了一个算法解释,其中最重要的一个可能是使用分层协议栈实现代码的最优性。

英文摘要:

In this paper, we consider a network communications problem in which multiple correlated sources must be delivered to a single data collector node, over a network of noisy independent point-to-point channels. We prove that perfect reconstruction of all the sources at the sink is possible if and only if, for all partitions of the network nodes into two subsets S and S^c such that the sink is always in S^c, we have that H(U_S|U_{S^c}) < \sum_{i\in S,j\in S^c} C_{ij}. Our main finding is that in this setup a general source/channel separation theorem holds, and that Shannon information behaves as a classical network flow, identical in nature to the flow of water in pipes. At first glance, it might seem surprising that separation holds in a fairly general network situation like the one we study. A closer look, however, reveals that the reason for this is that our model allows only for independent point-to-point channels between pairs of nodes, and not multiple-access and/or broadcast channels, for which separation is well known not to hold. This ``information as flow'' view provides an algorithmic interpretation for our results, among which perhaps the most important one is the optimality of implementing codes using a layered protocol stack.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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