Sum-Networks From Incidence Structures: Construction and Capacity Analysis
Sum-Networks From Incidence Structures: Construction and Capacity Analysis
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DOI:
10.1109/tit.2017.2765661
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发表时间:
2016-11
影响因子:
2.5
通讯作者:
Ardhendu Shekhar Tripathy;A. Ramamoorthy
中科院分区:
文献类型:
--
作者:
Ardhendu Shekhar Tripathy;A. Ramamoorthy
A sum-network is an instance of a function computation problem over a directed acyclic network, in which each terminal node wants to compute the sum over a finite field of the information observed at all the source nodes. Many characteristics of the well-studied multiple unicast network communication problem also hold for sum-networks, due to a known reduction between the two problems. In this paper, we describe an algorithm to construct families of sum-network instances using incidence structures. The computation capacity of several of these sum-network families is evaluated. Unlike the coding capacity of a multiple unicast problem, the computation capacity of sum-networks depends on the characteristic of the finite field over which the sum is computed. This dependence is very strong; we show examples of sum-networks that have a rate-1 solution over one characteristic but a rate close to zero over a different characteristic. In addition, a sum-network can have arbitrarily different computation capacities for different alphabets.