直接序列扩频信号检测算法的研究及FPGA实现

发布时间：2018-03-11 15:49

本文选题：直接序列扩频　切入点：成型滤波器　出处：《西安电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：本文首先从扩频通信(直接序列扩频)的原理开始,简单介绍了一些常用的扩频码,如m序列,Gold序列。然后着重开始讲解通信系统中较为常用的一些滤波器,如基带的成型滤波器(本文选取升余弦滤波器),变采样率的滤波器,如内插器、抽取器等,详细分析了内插器中一种高效的适合硬件电路来实现的CIC插值滤波器,接着又介绍了任意比率的插值滤波器——法罗滤波器,该滤波器适用于信号的采样率和系统的最高频率相差不大的情况下,比一般的先插值再抽取的滤波器应用更加灵活。第四章讲了扩频信号检测的算法,有平方倍频法,逐段方差法,四次均值法,对于每一种算法都进行了理论分析并用Matlab进行了仿真,最后结合算法复杂度以及资源的利用率,选用四次均值法。最后基于前面的内容,产生出扩频信号,并在硬件平台上进行了实现,进行检测。硬件平台为ISE12.1,配合仿真的软件为Modelsim 6.5。检测后发现,四次均值法能顺利完成指标的各项要求。
[Abstract]:Starting with the principle of spread spectrum communication (direct sequence spread spectrum), this paper introduces some common spread spectrum codes, such as m sequence Gold sequence, and then explains some filters commonly used in communication system. For example, baseband shaping filter (this paper selects raised cosine filter, variable sampling rate filter, such as interpolator, decimator, etc., and analyzes in detail an efficient CIC interpolation filter which is suitable for hardware circuit. Then, an arbitrary ratio interpolation filter, Farrow filter, is introduced. The filter is suitable for the case where the sampling rate of the signal and the maximum frequency of the system are not different from each other. It is more flexible than the ordinary filter with interpolation and decimation. Chapter 4th describes the spread spectrum signal detection algorithm, which includes the squared frequency doubling method, the piecewise variance method, the fourth-order mean method, Each algorithm is theoretically analyzed and simulated with Matlab. Finally, combining the complexity of the algorithm and the utilization of resources, the four-order mean method is selected. Finally, based on the previous contents, the spread spectrum signal is generated. The hardware platform is ISE12.1and the simulation software is Modelsim 6.5. after testing, it is found that the four-order mean method can fulfill the requirements of the index successfully.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN914.42;TN911.23

【相似文献】