CIF: Small: Approaching Capacity in High Throughput Communication Systems with Incremental Redundancy

产生数字信息的能力日益增强，人们对消费数字信息的渴望日益强烈，这就产生了以更高的速度交流信息的需求。自由空间光通信和毫米波无线通信系统力争达到超过100Gbps的速率。光纤支持每秒太比特的通信。这些系统需要当前牺牲性能的高速解码电路，以利用可用的计算资源来满足延迟要求。这项研究开发了高吞吐量通信的新技术，目标是在达到理论性能限制的同时以合理的复杂性满足延迟要求。除了为高通量系统的实际解决方案提供一条新的途径外，这项研究的更广泛的影响还包括培训研究生以支持美国在通信技术领域的持续领导地位，以及为本科生提供实践研究经验以维护供应我国的管道？S继续需要多样化的、训练有素的和创新的工程师。这项研究探索了一种新的范式，在这种新范式中，许多低复杂度的解码器并行工作，以较短的平均块长度解码变长码。短分组长的定长码不能接近香农容量，但平均短分组长的可变长码确实接近容量。可变长码传统上是用反馈实现的，因此仅当接收器请求时才传输递增冗余。这项研究在不使用反馈的情况下传输增量冗余，利用网络编码和遍历等技术仅向需要的并行解码器提供冗余。在没有反馈的情况下递送递增冗余的问题被框架化为在接收器具有边信息的联合信源-信道编码问题。这项研究的主要目标是生产能够在高吞吐量下接近容量的低复杂性系统。

The growing ability to generate digital information and the hunger to consume that information create a need to communicate information at ever-higher rates. Free-space optical and millimeter wave wireless communication systems strive to achieve rates exceeding 100 Gbps. Optical fiber supports terabit-per-second communications. These systems require high-speed decoding circuits that currently sacrifice performance to meet latency requirements with available computational resources. This research develops new techniques for high-throughput communications with a goal of achieving theoretical performance limits while meeting latency requirements with reasonable complexity. In addition to providing a new path for practical solutions for high-throughput systems, the broader impacts of this research include the training of graduate students to support continued leadership of the United States in communications technology as well as hands-on research experiences for undergraduates to maintain the pipeline that will supply our country?s continuing need for diverse, well-trained, and innovative engineers.This research explores a new paradigm in which many low-complexity decoders work in parallel, decoding variable-length codes with short average block-lengths. Fixed-length codes with short block-lengths cannot approach the Shannon capacity, but variable-length codes with short average block-lengths do approach capacity. Variable-length codes are traditionally implemented with feedback so that incremental redundancy is transmitted only when requested by the receiver. This research transmits incremental redundancy without the use of feedback, utilizing techniques such as network coding and ergodicity to deliver redundancy only to those parallel decoders that need it. The problem of delivering incremental redundancy without feedback is framed as a joint source-channel coding problem with side information at the receiver. The primary goal of this research is to produce low complexity systems that can approach capacity at high throughput.