混合分代网络编码的解码时延分析

Decoding time delay analysis for network coding with multi-generation mixing

采用网络编码方式能够有效提高网络的吞吐量,混合分代网络编码通过引入不同代之间的相关性,进一步提高了译码成功的概率,但是混合分代网络编码的计算复杂度和解码时延也相应增加了。在混合分代网络编码中冗余编码包有不同的添加方式,第一种方式是把冗余编码包分散添加到各个分代中,在这种方式中,每个分代的冗余编码包是和各个分代的编码数据包同时生成的,对所有小于它所在分代位置序号的分代有保护作用;第二种方式是把冗余编码包和最后一个分代的编码数据包一起发送,在这种方式中,冗余编码包对所有的分代有保护作用。主要对这两种混合分代网络编码的解码时延进行分析,研究表明第一种方式的解码时延小于第二种方式。

Network coding has contributed a lot for improving the throughput of network. Network coding with multi-generation mixing（ MGM） increases the successful decoding probability through grouping different generations into a mixing-generation.However,the cost is high calculation complexity and large decoding time delay. Since extra packets protect more than one gene-ration,there were different options for sending these protective extra packets（ redundancy） with MGM. One option was to distribute redundancy over mixing set generations. In this case and for higher position index of a generation the redundant encodings associated with that generation protect more of the mixing set generations. Another option was to send the redundant encodings with the last generation of the mixing set. In this case the redundant encodings protected all mixing set generations.This paper analyzed the two options and simulation results showed that the first option had lower decoding time delay than the second option.