超宽带信号的研究教程.doc

超宽带信号的研究 摘 要 随着美国联邦通信委员会(FCC)对超宽带技术发布的初步规定及对其所作的定义，超宽带脉冲无线电技术成了民用和军用研究的热点。与传统通信技术不同的是，UWB 是一种无载波通信技术，利用纳秒至微微秒级的非正弦波窄脉冲传输数据，所占的频谱范围很宽，适用于高速、近距离的无线个人通信。UWB 脉冲极短，直达波与多径反射、折射波，在时间上不易重叠，因此，其时间分辨率强，适合于多径分量丰富的室内无线信道传输；本文首先介绍了超宽带通信的背景及意义，分析了国内外研究现状和超宽带技术的主要研究方向，然后通过对超宽带信号的研究，引出直接序列扩频超宽带信号，通过推导并分析了DS-UWB 信号的功率谱，指出DS-UWB 信号的功率谱是由发送脉冲信号的频谱和编码频谱共同决定，并且用计算机进行仿真，证实了伪随机码周期越长，频谱越平坦。 关键词：超宽带；直接序列扩频；功率谱密度；通信技术 Study of Ultra Wide Band Signal Abstract With the United States Federal Communications Commission (FCC) on the ultra wide band technology released the preliminary requirements and its definition, ultra wide band impulse radio technology has become a hot spot for civil and military research.Different from traditional communication technology, UWB is a non carrier communication technology, using nanosecond and picosecond non sine wave narrow pulse data transmission, occupied a wide spectral range for in high speed, short distance wireless personal communication .The UWB pulse is very short, direct wave and multipath reflection, refraction,which is not easy to overlap in time.Therefore, its time resolution is strong, and it is suitable for the indoor wireless channel transmission with rich multipath component.This paper firstly introduces the background and significance of ultra wide band communication.The current research status and the main research direction of ultra wide band technology are analyzed. Then through the research of ultra wide band signal and direct sequence spread spectrum ultra wide band signal.By deducing and analyzing the power spectrum of the DS-UWB signal, the power spectrum of the DS-UWB signal is determined by the spectrum of the transmitted pulse signal and the coding spectrum.And using the computer simulation, it is proved that the pseudo random code cycle is longer, the spectrum is flat. Keywords： Ultra wide band;Direct sequence spread spectrum;Power spectral density;Communication technology 目 录