基于网络编码的无线网络容量分析

Research on the Capacity of Wireless Networks Based on the Network Coding

无线网络容量一直是无线网络领域的研究热点,而网络编码通过赋予中间节点对接收数据包进行编码、组合的能力,可以有效提高网络容量,达到最大流—最小割定理确定的理论上限。本文在Gupta和Kumar提出的信号干扰噪声比模型基础上,首先分析网络节点均匀分布时发送节点与目的节点进行多跳传输的无线网络容量计算方法;接着推导出了基于网络编码的无线网络容量计算公式,并利用MATLAB中求解线性规划问题的函数linprog()求解网络最大流及各链路流量,以此求出无线网络容量上界。通过对无线网络容量上界进行MATLAB仿真,得到如下结论:无线网络容量上界随节点数量的增加呈现先增加后减少的趋势;且当节点数量趋于无穷大时,网络容量趋于零;与传统的存储转发模式相比,采用网络编码有利于提高网络容量。

The network capacity has been a hotspot in the field of wireless network. Network coding has the advan-tage that the intermediate node can encode the data it receives,which can efficiently improve end-to-end through-put. In this paper,we first analyze the multi-hop capacity of wireless network based on the signal-to-interference ra-tio model proposed by Gupta. Then an algorithm of wireless network capacity based on the network coding is pro-posed and to compute the upper bound of the network capacity,we obtain the network maximum flow and each linkflow by utilizing the method which solves linear programming problems in the MATLAB. The simulation experi-ments show that the capacity using network coding is higher than that of traditional routing strategy and the upperbound of network capacity has a trend of first increasing and then decreasing with the number of nodes.