无线网络中机会网络编码与代数网络编码相结合的重传方案

ROANC: Wireless Network Retransmission Scheme Combined with Opportunity Network Coding and Algebraic Network Coding

提出无线网络中机会式网络编码与代数网络编码相结合的重传方案,采用代数网络编码策略来解决非关联特性包的重传问题.该方案分两个阶段,第一阶段采用机会网络编码恢复关联包的丢包;第二阶段采用代数网络编码对非关联包进行包恢复.代数网络编码阶段把机会式网络编码恢复关联包后的矩阵作为代数网络编码的初始信息矩阵,依据该矩阵的满秩分解的结果筛选出合适的编码矩阵,再删除该矩阵中的关联包所对应的列使得非关联包的转移矩阵的行列式不为零,接收端依据转移矩阵一次可恢复多个非关联包.该方案的优势在于充分利用机会网络编码编解码容易,与代数网络编码一次可恢复多个非关联丢包的优势,最大化编码增益,降低了重传开销.仿真结果证明该重传方案优于典型机会式网络编码的重传性能.

ROANC （ wireless network Retransmission scheme combined with Opportunity network coding and Algebraic Network Cod- ing） is proposed in this paper. The scheme is divided into two stages,the first stage is to search for CRP（ Correlated loss Packets） in PIM （ Packets Information Matrix ） , and use XOR operation to recover CRP , this stage can maximize coding gain and enhance algebraic network coding decoding condition. The second stage is to recover UCRP （UnCorrelated loss Packets） using algebraic network coding to improve UCRP recovery efficiency. In algebraic network coding stage, taking the current PIM as the initial inputting matrix after the first stage recovery based on the opportunity network coding. According to the full rank decomposition results to this matrix, select the appropriate coding matrix, then remove the redundant columns according to the number of packets recovered at the first stage to make the uncorrelated packets transfer matrix determinant nonzero. And the multiple uncorrelated packets can be recovered according to the final transfer matrix. This scheme has the following advantages： making full use of the simple operation of the opportunity network coding encoding and decoding, and the simultaneous recovery of the multiple uncorrelated loss packets and the perfect matrix algebra theory. The final goals are to maximize the decoding achievement and reduce recovery cost. The simulation results show that this scheme is superior to that of the traditional classical retransmission schemes based on network coding.