中断和失真容忍的空间通信技术研究

项目名称： 中断和失真容忍的空间通信技术研究

项目编号： No.61201183

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 电子学与信息系统

项目作者： 杜冰

作者单位： 清华大学

项目金额： 27万元

中文摘要： 针对空间通信由飞行器高动态造成的空地信道时变、中断和失真条件下的多媒体信息传输问题，提出在信道衰落失真状态下的基于信源多描述分层的联合信源信道编码，将信源压缩成多个独立的失真序列，实施不等差错保护，达到端到端的最优性能；提出在信道渐进中断状态下的混合模拟数字传输方法，利用模拟传输的"优雅降级"解决在超低信噪比下数字传输的"门限效应"问题，并兼顾数字传输的高效性；提出基于信源多描述及混合模拟数字的多空间平台协作传输，确保延时受限的高速多媒体数据通信。综上，本项目利用联合信源信道和混合模拟数字的协作传输，实现数据多媒体业务在时变空地信道下的传输，并在软件无线电平台上实现一套空间通信关键技术软件包。

中文关键词： 模拟域；联合信源信道编码；低密度奇偶校验码；协作通信；邻接矩阵

英文摘要： Due to the radical dynamics of the spacecraft, the time-variant space-to-ground channel suffers frequent outage and unknown distortion, especially when massive multimedia is transmitted. A joint source-channel coding based on multiple description layered source coding (MDLC) is proposed to deal with expected channel distortion; multiple distorted independent descriptions of the source are coded by unequal error protection channel coding to achieve optimal end to end performance. Then, to overcome the outage event caused by low-altitude angle of the spacecraft, a hybrid digital-analog (HDA) transmission scheme is brought forward; HDA is able to solve the problem that below certain SNR, the digital system performance degrades drastically, by employing "gracefully degrading" feature of the analog system. Moreover, a cooperative communication based on MDLC and HDA is presented to ensure delay-constraint massive multimedia transmission. This project develops a MDLC and HDA based cross-layer cooperative transmission strategy, to break through the key technologies of multimedia transmission in time-variant space-to-ground channel and realize a corresponding software package.

英文关键词： Analog fields；Joint source-channel coding；LDPC；Cooperative communications；Adjacency matrix