Burst-Erasure Correcting Codes With Optimal Average Delay
Burst-Erasure Correcting Codes With Optimal Average Delay
复制标题
具有最佳平均延迟的突发擦除校正码
DOI：
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发表时间：
2017
影响因子：
2.5
通讯作者：
Yuval Cassuto
中科院分区：
文献类型：
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作者：
N. Adler;Yuval Cassuto
低延迟编码的目标是通过最小化数据包擦除和其重构之间的时间来保护通信流免受擦除突发。以前的工作集中在恒定延迟的情况下，所有擦除的数据包需要表现出相同的解码延迟。我们考虑异构延迟的情况下，其目标是最小化在一个突发擦除数据包的平均延迟。我们推导出平均情况下的延迟下限，并表明它们仅在单个速率点<inline-formula><tex-math notation="LaTeX">$R=0.5$</tex-math></inline-formula>时才匹配恒定延迟界限。然后，我们构造代码的最佳平均延迟的整个范围内的码率。对于速率<inline-formula><tex-math notation="LaTeX">$R> 0.5$</tex-math></inline-formula>的构造对于每个擦除实例实现最优，而对于速率<inline-formula><tex-math notation="LaTeX">$R>0.5$</tex-math></inline-formula>的构造对于所有突发实例的<inline-formula><tex-math notation="LaTeX">$（1-R）/R$</tex-math></inline-formula>部分是最优的，并且对于剩余部分接近最优。本文还研究了传感器通信应用中的延迟异质性的好处。结果表明，精心设计的代码可以显着提高时间精度在接收节点以下擦除突发事件。
The objective of low-delay codes is to protect communication streams from erasure bursts by minimizing the time between the packet erasure and its reconstruction. Previous work has concentrated on the constant-delay scenario, where all erased packets need to exhibit the same decoding delay. We consider the case of heterogeneous delay, where the objective is to minimize the average delay across the erased packets in a burst. We derive delay lower bounds for the average case, and show that they match the constant-delay bounds only at a single rate point <inline-formula> <tex-math notation="LaTeX">$R=0.5$ </tex-math></inline-formula>. We then construct codes with optimal average delays for the entire range of code rates. The construction for rates <inline-formula> <tex-math notation="LaTeX">$Rleq 0.5$ </tex-math></inline-formula> achieves optimality for every erasure instance, while the construction for rates <inline-formula> <tex-math notation="LaTeX">$R>0.5$ </tex-math></inline-formula> is optimal for a <inline-formula> <tex-math notation="LaTeX">$(1-R)/R$ </tex-math></inline-formula> fraction of all burst instances and close to optimal for the remaining fraction. The paper also studies the benefits of delay heterogeneity within the application of sensor communications. It is shown that a carefully designed code can significantly improve the temporal precision at the receiving node following erasure-burst events.