Traditional channel coding with feedback constructs and transmits a codeword only after all message bits are available at the transmitter. This paper joins Guo & Kostina and Lalitha et. al. in developing approaches for causal (or progressive) encoding, where the transmitter may begin transmitting codeword symbols as soon as the first message bit arrives. Building on the work of Horstein, Shayevitz and Feder, and Naghshvar et. al., this paper extends our previous computationally efficient systematic algorithm for traditional posterior matching to produce a four-phase encoder that progressively encodes using only the message bits causally available. Systematic codes work well with posterior matching on a channel with feedback, and they provide an immediate benefit when causal encoding is employed instead of traditional encoding. Our algorithm captures additional gains in the interesting region where the transmission rate mu is higher than the rate lambda at which message bits become available. In this region, transmission of additional symbols beyond systematic bits, before a traditional encoder would have begun transmission, further improves performance
翻译:只有在发报器上提供所有信息位子之后, 传统频道才使用反馈编码, 传统频道才构建并传输编码词。 本文将Guo & Kostina 和 Lalitha 等加入到开发因果编码( 或累进) 方法中, 使发报器可以在第一个信息位到达后立即开始传输编码符号。 在Horstein、 Shayevitz 和 Feder 以及 Naghshvar 等的工作基础上, 本文扩展了我们以前传统的后背镜匹配的计算高效系统算法, 以生成一个四阶段编码器, 该编码器仅使用信息位子因果可获取。 系统代码与带反馈的事后编码匹配运作良好, 当使用因果编码而非传统编码时, 它们会立即带来好处 。 我们的算法捕捉了有趣的区域中的额外收益, 那里的传输率高于信息位子的 。 在这个区域, 在传统编码器开始传输之前, 将传送更多的符号, 而不是系统比子, 进一步改进性, 。