CAREER: Channel Coding for Satellite and Mobile Communications

通过卫星和无线通信网络的语音和数据通信服务的快速增长已经导致将数字通信技术中的最新技术水平快速结合到当前系统中。 这些网络的下一代将要求在系统的每一个点上使用更复杂的技术。 显然，信道编码将是无处不在的，以对抗信道传输效应，更有效地利用系统资源，并促进多用户接入。 本项目关注的是新的信道编码类的调查，以满足这些需求。特别是，正在开发新的时变码类，以降低发射机功率要求，并使系统能够在接近理论极限的情况下以几个服务质量水平工作。 此外，正在开发新的迭代解码算法和软信息交换范例，以便为定时和同步以及多用户检测等各种系统功能提供稳健的综合解决方案。时间的分析和表现-在信息论的基本定理和下一代卫星和无线通信系统的需求的背景下改变信道编码。 正在研究的代码类包括并行和串行级联的块和网格码和新类的周期性时变卷积码。 这些编码方案的性能进行了研究的加性白色高斯噪声信道和各种多径衰落信道模型。 正在做出特别的努力来开发包括非对称并行级联的代码，其具有短块长度和在各种错误率下的接近容量性能，用于移动的无线通信。 迭代解码和软信息交换的原理也被用来增强其他系统功能。 这包括与软输出信道解码算法和新颖的联合源/信道编码结构交互的低信噪比定时和同步算法。 信道码的迭代解码也被研究作为开发迭代多用户检测算法的一种手段，该算法在高负载多用户系统上实现接近单用户容量。

The rapid growth in voice and data communications services over satellite and wireless communication networks has resulted in the rapid incorporation of the state of the art in digital communication techniques into current systems. The next generation of these networks will demand even more sophisticated techniques at every point in the system. It is evident that channel coding will be ubiquitous in order to combat channel transmission effects, to more efficiently utilize system resources and to facilitate multiuser access. This project is concerned with the investigation of new classes of channel codes to meet these demands. In particular, new classes of time varying codes are being developed to reduce transmitter power requirements and to enable systems to operate close to theoretical limits with several levels of quality of service. In addition, new iterative decoding algorithms and soft information exchange paradigms are being developed to provide robust integrated solutions to a variety of system functions such as timing and synchronization and multiuser detection.This project involves the design, analysis and performance of time-varying channel codes in the context of the basic theorems of information theory and the demands of the next generation of satellite and wireless communication systems. The classes of codes being studied include parallel and serial concatenation of block and trellis codes and new classes of periodically time varying convolutional codes. The performance of these coding schemes is studied for both the additive white Gaussian noise channel and a variety of multipath fading channel models. A particular effort is being made to develop codes, including asymmetric parallel concatenations, with short block lengths and near capacity performance at a variety of error rate for mobile wireless communications. The principle of iterative decoding and soft information exchange is also being exploited to enhance other system functions. This includes low signal to noise ratio timing and synchronization algorithms that interact with soft output channel decoding algorithms and novel joint source/channel coding structures. Iterative decoding of channel codes is also being investigated as a means of developing iterative multiuser detection algorithms that achieve near single user capacity on highly loaded multiuser systems.