论文标题
通过反馈的DMC流媒体流式传输的可靠性功能
Reliability function for streaming over a DMC with feedback
论文作者
论文摘要
通常，在通道编码和块编码上下文中研究了后匹配 - 源符号是齐射的分布，并且在传输前的编码中完全知道。在本文中，我们考虑了一个流源，其符号以一系列确定性时间到达编码器。我们通过反馈通过离散的无内存通道（DMC）流式传输的联合源通道编码（JSCC）可靠性功能。我们提出了一个新颖的瞬时编码阶段，该阶段在符号到达期间运行，并在传输块编码方案后获得流式传输的JSCC可靠性功能，该方案可实现经典源的JSCC可靠性函数，其符号在传输前可以完全访问。在瞬时编码阶段，将不断发展的消息字母分配为组，编码器确定包含符号到目前为止的组的索引，并将随机分配到随机分布以匹配传输索引的分布到容量处理的一个。令人惊讶的是，流媒体的JSCC可靠性功能等于完全可访问的源，这意味着在传输之前的整个符号序列的知识在可靠性函数上没有任何优势。为了通过对称2输入DMC进行流式传输，我们提出了一个瞬时的小型差异（SED）代码，该代码不仅可以实现JSCC可靠性函数，而且还可以用来通过噪声通道稳定不稳定的线性系统。我们设计低复杂性算法以实现瞬时编码阶段和瞬时SED代码。虽然可靠性函数是针对非分类DMC的，但对于退化DMC，我们设计了一个瞬时编码的代码，该代码对于低于Shannon JSCC限制的所有速率都达到了零误差。
Conventionally, posterior matching is investigated in channel coding and block encoding contexts -- the source symbols are equiprobably distributed and are entirely known by the encoder before the transmission. In this paper, we consider a streaming source, whose symbols arrive at the encoder at a sequence of deterministic times. We derive the joint source-channel coding (JSCC) reliability function for streaming over a discrete memoryless channel (DMC) with feedback. We propose a novel instantaneous encoding phase that operates during the symbol arriving period and achieves the JSCC reliability function for streaming when followed by a block encoding scheme that achieves the JSCC reliability function for a classical source whose symbols are fully accessible before the transmission. During the instantaneous encoding phase, the evolving message alphabet is partitioned into groups, and the encoder determines the index of the group that contains the symbols arrived so far and applies randomization to match the distribution of the transmitted index to the capacity-achieving one. Surprisingly, the JSCC reliability function for streaming is equal to that for a fully accessible source, implying that the knowledge of the entire symbol sequence before the transmission offers no advantage regarding the reliability function. For streaming over a symmetric 2-input DMC, we propose an instantaneous small-enough difference (SED) code that not only achieves the JSCC reliability function but also can be used to stabilize an unstable linear system over a noisy channel. We design low complexity algorithms to implement both the instantaneous encoding phase and the instantaneous SED code. While the reliability function is derived for non-degenerate DMCs, for degenerate DMCs we design a code with instantaneous encoding that achieves zero error for all rates below Shannon's JSCC limit.
