节点文献
脉冲无线超宽带系统收发体制性能研究
【作者】 周毅；
【导师】 杨万麟；
【作者基本信息】 电子科技大学 ， 信息获取与探测技术， 2008， 硕士
【摘要】 超宽带通信系统从发射到接收存在许多关键的和独具特色的技术,其中特殊的发射调制体制、信道模型和相关接收机结构是众多技术中尤为重要和基础的关键技术。在复杂的信道环境中(加性白噪声、多径、多用户、用户随机接入等),任何参数(包括信道、调制和接收机参数)的改变都会对整个系统的性能造成影响。本文选择这些技术中常用的典型对其进行理论上的仿真上的分析对比,研究不同技术不同参数对系统性能造成的影响。在理论和仿真分析过程中,本文选择较有代表性的IEEE标准UWB信道为基础进行理论和仿真分析。并将论文结构依据信号的传输过程分为调制和接收体制两大部分。在调制体制的分析中,PAM、PPM两种基础而且重要的常用方法被结合DS、TH两种不同的多址接入方式进行理论和仿真分析,并研究了不同参数对不同系统的性能影响,给出对两种调制方式进行对比;作为基本泛型模板本文分别在DS、TH两种多址接入方式下给出了对PSM调制的性能分析,统一了其它大多数调制形式的性能公式;同时,本文结合对不同调制方式的分析给出了DS和TH两种多址接入方法的优劣比较;另外,本文对于目前在UWB-Rake结构性能分析中普遍认定的抽头输出不相关的假设提出不同意见,并给出修正方案。为了使论文结构和逻辑完整,本文给出了对于Rake接收机不同结构和不同组合方式的分析。在接收机结构方面,存在三种不同的结构:ARake、PRake和SRake,对于不同的结构在不同干扰源下的表现进行研究;在组合方式上,本文讨论了三种具有代表性的组合方式:MRC、EGC和MMSE,在白噪声和多用户干扰下对它们的性能进行对比和研究。通过整个论文的讨论和研究建立起了关于这些关键技术细节分析,和对整体系统的把握。
【Abstract】 There’re many sorts of important and peculiar technologies existed in the field of Ultra Wideband (UWB) wireless communication. Among them, the peculiar modulation technology, channel model as well as receiver structure are the most important and fundamental ones. Because of the complexity of the wireless channel, any change in the parameters of channel model, modulation method or receiver could dreadfully affect the system performance. This dissertation concerns those typical technologies with theoretical and simulating approaches.In order to get a more accurate result, the theoretical and simulating analysis is performed with the standard channel model presented by IEEE. And according to the process of the signal transmission, the structure of the dissertation is arranged generally in two parts: signal modulation and signal reception. In the analysis of signal modulating methods, two kinds of important methods, PAM and PPM, are studied, with which two different MAC strategy, DS and TH, are compounded, using both theoretical and simulating approaches. Especially, the effect of different parameters on the performances of communication systems are carefully studied, and the comparison of those modulating methods are given. As the template of all modulating methods, the performance of PSM method is studied under both DS and TH MAC strategy;Meanwhile, this dissertation studied the differences of DS and TH MAC method; and hold a different opinion on the prevail assumption that the output signal from different fingers of UWB-Rake receiver are totally unrelated. The is also proposed as an option of modification.To complete the integrity and logic of the dissertation, different structure and combining methods of the receiver is also well studied. As the aspect of receiver structure, there’re three kinds of them existed, which are ARake, PRake and SRake, all those structure are studied under the interference of white noise and multi-users. As the aspect of combining methods, three typical ones, which are MRC, EGC and MMSE, are studied under the same interference.