Theory and Design of Rateless Codes for Wireless Communication

本研究旨在解决无线通信应用中无速率码的理论和设计中的几个关键问题。与传统的编码设计不同，无速率码不需要规定的传输数据速率。相反，所编码的消息被传输，直到接收器发出信号表示它已相继解码了所述消息为止。该技术允许数据传输适应已实现的信道质量，这在无线网络应用中通常是未知的。本研究中使用的实现无速率传输的主要方法包括使用多层低速率子码和连续对消接收器。研究了基本性能限制和具体规范设计中的相关问题。具体而言，研究人员通过使用重复编码和抖动编码技术，研究了未知信噪比的加性高斯白噪声（AWGN）信道中的无速率编码设计。然后将该方法推广到未知容量的二进制对称信道、多输入多输出（MIMO）信道以及包括多接入信道、中继信道在内的网络应用，以及各种无速率环境下的协作传输体系结构。本研究的最终目标是解决增量信息传输的基本问题，并为开发新一代应用所需的健壮和灵活的无线基础设施奠定理论基础。

This research is aimed at addressing several key issues in the theory and designs of rateless codes for wireless communication applications. Unlike conventional coding designs, a rateless code does not require a prescribed transmission data rate. Instead, the encoded messages are transmitted until the receiver signals that it has successively decoded the message. This technique allows the data transmission to adapt to the realized channel quality, which is often not known in wireless network applications. The main approach used in this research to achieve rateless transmissions involves the use of multiple layers of low rate sub-codeswith successive cancellation receivers. Related issues in the fundamental performance limits and specific code designs are studied.Specifically, the investigators examine the rateless code designs in additive white Gaussian noise (AWGN) channels with unknown signal-to-noise ratios, by using repetition codes and dithering encoding techniques. The approach is then generalized to study binary symmetric channels with unknown capacities, multiple-input multiple-output (MIMO) channels, as well as network applications including multiple access channels, relay channels, as well as a variety of cooperative transmission architectures in the rateless context. The ultimate goal of this research is to addressthe fundamental issue of incremental information transmissions, and to develop a theoretical foundation for the development of robust and flexible wireless infrastructure needed for a new generation of applications.