超宽带通信点分多址理论研究

项目名称： 超宽带通信点分多址理论研究

项目编号： No.60802015

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 石油、天然气工业

项目作者： 田亚飞

作者单位： 北京航空航天大学

项目金额： 20万元

中文摘要： 超宽带系统使用低功率谱密度超大带宽信号进行通信，但是干扰问题限制了它的传输距离，利用短脉冲超宽带信号的空间分辨能力，形成时空聚焦，可以使信号向某一个空间位置定点传输。空间资源是一个巨大的系统资源，以位置划分信道，可以大大提升区域内的空间容量。而时空聚焦可以有效地降低对共存系统的干扰，大大扩展超宽带系统的作用距离。本项目研究了以下一些关键问题：分析了时空聚焦增益和干扰结构与超宽带系统参数和信道环境的关系，得到了共存约束下点分多址超宽带系统的传输距离和空间容量；提出了提高聚焦增益、降低多径干扰、多用户干扰及对共存系统干扰的发射端预处理算法和接收端低复杂度均衡算法；使用节点协作提高散射体不足的环境下系统的适应性，提出了非对称信道下的中继传输方案。点分多址理论是超宽带技术和MIMO技术的融合与创新，为超宽带通信的发展提供了新的思路，具有广泛的应用潜力。

中文关键词： 超宽带通信；时空聚焦；多用户干扰；预处理；协作中继

英文摘要： Ultra-wideband (UWB) communication system employs signals with low power spectrum density and large bandwidth, but its coverage is restricted by interference problem. UWB signals can resolve a large number of multipath components in densely scattered channels. Exploiting these characteristics, the transmitted signal can be focused to a specific time instant and geometrical position. Space is a huge system resource, by sharing the channel with different positions, the spatial capacity can be dramatically improved. Space-time focusing technique reduces interference to coexisting systems and thus extend the coverage of UWB systems. In this project, we analyzed the space-time focusing gain and its relationship with UWB system parameters and channel environments. The spatial capacity of UWB networks with space-time focusing transmission is obtained given the coverage and coexistence constraint. We proposed transmitter-side preprocessing algorithm and receiver-side equalization algorithm to improve focusing gain, and to reduce multipath, multiuser and cochannel interferences. Cooperative relay is exploited to help space-time focusing in sparsely scattered environments, and transmission schemes in asymmetric relay channels are developed. The proposed location-based multiple-access method is an innovative integration of UWB and MIMO communication techniques, and has wide range potential applications.

英文关键词： ultra-wideband communications; space-time focusing; multiple-user interference; preprocessing; cooperative relay