一种改进的即时解码网络编码的无线重传策略

An Improved Wireless Retransmission Strategy Based on Instantly Decodable Network Coding

为了充分利用网络编码的优势,文中提出一种改进的基于即时解码网络编码的无线重传策略。该策略从图论(编码机会)的角度出发,为了减少编码数据包的重传次数,在考虑剩余编码机会和剩余数据包需求的条件下选择编码数据包,使每一步选择的重传编码数据包组合能够保证剩余编码密度(实际编码机会和最大编码机会之比)最大,并且针对同等编码密度的情况,进一步考虑平均解码时延最小者为所选择的网络编码重传方式。研究表明,所提出的策略相对于服务最大需求数据包策略和随机编码子集选择策略,能够进一步减少重传次数,降低平均解码时延。

To take full advantage of the advantages of network coding, an improved wireless retransmission strategy based on instantly decodable network coding is proposed in this paper. This strategy is researched with graph theory. In order to reduce the numbers of broadcast retransmissions, when doing the selection of a coding combination, the remaining coding opportunity and remaining packet requests are considered. So each coding packet of selection can maximize the remaining coding density （ the ratio of the number of actual coding opportunities to the maximum number of coding opportunities）. If the number of optimal selection is large with the same coding density, the retransmissions will be chosen to minimize the average decoding delay. Research illustrates that the strategy proposed in this paper is possible to reduce the numbers of retransmissions and average decoding delay compared with most wanted packet serving strategy and random clique selection strategy.