【作者】 刘辉；

【导师】 傅丰林；

【作者基本信息】 西安电子科技大学 ， 通信与信息系统， 2010， 硕士

【摘要】 超宽带无线通信技术(UWB, Ultra Wide Band)的研发为人们解决无线通信频谱资源匮乏的问题提供了新的方案和思路。这种通信技术因其极宽的频谱范围,可以达到很高的信息传输速率,同时又兼具抗干扰性能强、发送功率小的优势。随着认知无线电技术的发展,UWB有了新的发展方向,认知超宽带(CUWB, Cognitive UWB)。CUWB较之传统的UWB有了长足进步。它的优势在于:可以对任意形状的辐射掩蔽进行匹配并且能够对任意频点窄带干扰进行避免。相应的,对所使用脉冲的性能也提出了更高的要求。本文的重点是基于PSWF(Prolate Spheroidal Wave Function)的超宽带脉冲产生算法的研究和改进。首先通过对PSWF脉冲产生算法的仿真,得出了“基于PSWF的脉冲产生算法最适合于CUWB技术”的结论。然后,为了使PSWF脉冲能够避免窄带信号的干扰,在PSWF脉冲产生算法的思路之上,分别改进出不同步长搜索法及使用滤波器的多频带脉冲组合法两种脉冲产生算法。通过在不同窄带干扰情况下的仿真发现,不同步长搜索法解决了以往算法中不能准确控制陷波点和陷波效果不稳定的问题,不但实现了任意频点的陷波功能,而且产生脉冲在任意陷波频点的功率谱密度维持在-75dBm左右;使用滤波器的多频带脉冲组合法陷波效果虽不及不同步长搜索法,但在保证陷波频点准确控制的同时,频谱利用率高于不同步长搜索法。更多还原

【Abstract】 The technology of UWB (Ultra Wide Band) provides a new scheme for people to solve the problem about scarcity of frequency resource. This technology can make a large throughput for its wide band, also, it has powerful noise-resistance and low radiated power. Along with the exploitation of Cognitive Radio, UWB has a new development, CUWB (Cognitive UWB). Comparing the traditional UWB, CUWB makes a considering improvement: it can match a variable emission mask and suppress a narrow band interference in any frequency. Correspondingly, it puts forward higher requirement for performance of UWB impulse.The article emphasized on research and improvement of algorithm of impulse generation based PSWF(Prolate Spheroidal Wave Function). At first, we educed a conclusion that the impulse based PSWF fits CUWB best through simulations, and then, in order to suppress a narrow band interference , we make out two algorithm of impulse generation,“Different steps searching”and“Multi-band impulses composing”.After many simulations in different situations, it seems that“Different steps searching”can solve the problem that the notch of spectrum can’t be controlled precisely and the result of spectrum suppressing isn’t stable in formal algorithm. Not only the notch of spectrum can be controlled precisely, but also the PSD in such notch is as low as -75dBm. Even though the result of spectrum suppressing by“Multi-band impulses composing”is not as good as“Different steps searching”,“Multi-band impulses composing”can acquire a higher utilization per cent in spectrum.更多还原