【作者】 王野秋；

【导师】 吕英华；

【作者基本信息】 北京邮电大学 ， 电磁场与微波技术， 2007， 博士

【摘要】 为了实现全球范围无缝覆盖的，可以同时进行语音、文本、图像、视频的高速多媒体通信，通信网络应该是包含多种通信技术的有线无线相结合的综合网络。在这样的背景下，由于超宽带(UWB)技术具有极大的带宽，极低的功率，可实现现有频率资源复用等显著特点，已经成为目前无线通信领域的热点之一。超宽带具有高传输速率、高可靠传输、高时间空间分辨率、低功率、低成本、小型化等优势，适合在短距离无线通信、高精度测距定位及工程探测等领域应用。目前超宽带研究热点与难点集中在信号波形设计、天线设计、传输信道模型研究、低成本低功耗集成电路研究、组网技术研究、高效调制技术研究、电磁兼容研究及快速同步技术研究等方面。本论文以UWB的两大本质特征——大带宽，低功率为主线，挖掘UWB在可靠通信容量及精确测距定位上的潜力，并同时研究与其他无线通信系统的共存性问题。论文内容包括：1．用等重码构建了一种新的称为多脉冲位置调制(MPPM)的UWB跳时调制方案，并对其在加性高斯白噪声(AWGN)下的信道容量、误码率、链路预算、功率效率、带宽效率及接收机复杂度等几个方面进行了分析。理论分析与数值比较结果表明，满足一定条件时，L进制的多脉冲位置调制(MPPM)可以比L进制的脉冲位置调制(PPM)具有更低的接收机复杂度，在数据容量、误码率及链路预算等指标上获得比L进制PPM及L进制的脉冲幅度调制(PAM)更好的性能，可以成为UWB短距离高速通信应用的一个很好的备选调制方案。2．用扩展等重码构建了一种称为双极性多脉冲位置调制(AMPPM)的新UWB跳时调制方案，并对接收机复杂度、误码率、信道容量、数据率、带宽效率，功率效率及发射功率限制下的最大可靠通信距离进行了分析。理论分析与数值结果都表明，当调制参数正确选择时，AMPPM可以在相同的条件下获得比PPM、PAM、双正交脉冲位置调制(BPPM)及新提出的MPPM更好的通信性能，也可成为UWB高速通信应用的一个很好备选调制方案。3．建立了三维积分模型分析并仿真了室内多个UWB设备对无线通信终端的合成干扰效果，分析了全视距及视距非视距混合两种情况，并且选择了GSM900，GSM1800，小灵通及TD-SCDMA四种系统手持机作为受干扰研究对象，分析是在FCC及ETSI两种UWB发射功率控制模板规范下进行的。通过理论分析与仿真结果得出了以下结论：1)所评估的无线通信系统抗UWB干扰能力按照GSM900＞GSM1800＞TD-SCDMA＞小灵通的顺序递减。2)ETSI规范对无线系统的保护强于FCC.当受干扰系统链路预算干扰保护在[13]dB范围内时，FCC UWB功率限制模板只能对GSM900有效保护，对其他三种系统只能达到临界干扰状态，而ETSI的标准对四种系统都能提供可接受的保护程度。本文提出的三维积分UWB干扰模型可以有效地评估立体分布的多UWB设备对窄带无线系统的干扰，为现代化办公楼UWB设备布置及UWB功率控制方面的研究提供了理论参考依据。4．提出了一种新的基于特殊序列(APA序列)的UWB测距算法.通过理论分析与仿真，可以证明，与传统序列相比，APA测距序列能在相同的条件下(相同的信道，相同的信噪比，相同的测距序列长度)获得更高的测距精度，而且如果增加APA序列的长度还可以进一步降低测距误差，但需要以更多的能量和时间为代价。5．设计了一种基于UWB测距的车辆平面定位系统，在理想情况下该系统最少可以使用2个参考节点，降低了系统成本。在非理想情况下，提出了通过增加参考节点进行方程解平均、增加测距次数进行多次测距平均和利用天线阵进行到达角测量来实现测距平面修正的三种改进算法。更多还原

【Abstract】 For realizing the service target of seamless coverage in a global range and providing high-data rate multimedia communication, the communication network should be an integrated network including several communication technologies which at lest consists of wireless and cable. Such being the case, ultra-wide band (UWB) has become a favourite technology for wireless communication due to its good characteristics such as ultra wide bandwidth, low power, frequency reusing and so on.UWB owns many advantages such as high transmission data-rate, high reliable transmission, high time and spatial resolution, low power, low cost, miniaturization and so on, which make UWB very suitable for short-range wireless communication, high precision ranging and positioning or detection application. The study topics for UWB include signal waveform design, antenna design, channel model research, IC design, network buildup, new modulation technology, EMC and so on.The work of this paper aims at developing UWB at the aspects of communication capacity, high accuracy ranging, and the co-existence ability between UWB and other narrow band wireless systems. All the work is based on the essential UWB characteristics of wide bandwidth and low power requirement.The contents of this paper include:1．A new time-hopping UWB modulation method called multi-pulse position modulation (MPPM) constructed by constant weight code (CWC) is proposed. And the performance of MPPM is analyzed in several aspects such as channel capacity, probability of symbol error, link budget margin, power efficiency, bandwidth efficiency and receiver complexity. Theory analysis and numerical results show that L-ary MPPM can perform better than L-ary pulse position modulation (PPM) and L-ary pulse amplitude modulation (PAM) do under some conditions. The proposed MPPM can be a good candidate for UWB short-range and high data-rate wireless communication application.2．A novel time-hopping UWB modulation scheme called ambipolarmulti-pulse position modulation (AMPPM) is proposed. The AMPPM signal is constructed by extending constant weight code (ECWC) and analyzed based on the existing biorthogonal pulse position modulation (BPPM) and MPPM. The error probability, receiver complexity, channel capacity, data-rate, bandwidth efficiency, power efficiency and maximum reliable transmission distance of AMPPM are derived over an additive white Gaussian noise (AWGN) channel. Theory analysis and simulation results show that AMPPM can get a better performance character than PPM, PAM, BPPM and MPPM do under the same condition. AMPPM could also be a good candidate for UWB high-data rate wireless application.3．Since the narrowband wireless systems could be disturbed by UWB devices, a 3D integral model is introduced to analyze the impact of UWB cumulative interference on the narrowband wireless systems, and the proposed model is divided into two situations which are LOS and LOS-NLOS mixture. The proposed analysis model can evaluate the UWB interference effect on victim receivers efficiently and deliver numerical evaluation results of both the anti-UWB interference ability of different wireless systems and the protection ability of different UWB emission masks. The analysis method and model can be a useful theoretical reference for the study on UWB devices layout in modern buildings and the UWB emission power control.4．A new UWB ranging algorithm based on a kind of special sequencecalled almost perfect autocorrelation (APA) sequence is introduced, and some theory and simulation results are given under AWGN channel and IEEE recommended UWB channel model respectively. The comparison results of ranging accuracy between the ranging systems with and without APA sequence show that the APA sequence can get higher ranging accuracy than the common sequence under the same condition, and increasing the length of the APA sequences can lead to better ranging precision but need more time and energy loss. So the APA sequence is a good candidate for UWB ranging system and the length of APA ranging sequence should be selected according to the particular application.5．Based on the UWB ranging technology, a plane vehicle positioning system is designed for the intelligent transport system which only needs two reference nodes in an ideal environment. And for improving the positioning accuracy of the proposed system under a non-ideal condition, another three algorithms based on solution-averaging, distance-averaging and angle of arrival (AOA) ranging plane amending are also introduced. The theory analysis and simulation results show that the proposed positioning system can perform vehicle positioning task and get a high positioning precision assisted by the modified algorithms.更多还原