FH/DS混合扩频通信系统及其抗干扰措施的建模仿真

【作者】 袁磊；

【导师】 李立萍；

【作者基本信息】 电子科技大学 ， 信息获取与探测技术， 2007， 硕士

【摘要】 扩展频谱通信作为新型的通信方式,由于其优良的多址接入、低截获概率、抗干扰和强保密等特性,使得它在军事通信、卫星通信、移动通信和C 3I系统中得到了广泛的应用。因此,本论文对FH/DS混合扩频通信系统的研究及其为了弥补扩频系统扩频增益的不足而采取抗干扰措施的研究在通信领域具有重要的现实意义。本文深入研究了FH/DS混合扩展频谱通信系统及其抗干扰措施,主要工作包含两部分的内容:FH/DS混合扩频通信系统关键技术的研究及一种FH/DS混合扩频通信系统的建模与仿真;FH/DS混合扩频通信系统中抗干扰模块的设计与仿真。第一部分研究了FH/DS混合扩频通信数字接收系统中的伪码同步和载波同步的方法,通过对其数学模型和参数设计进行分析,建立在simulink下的动态系统仿真模型,通过仿真实验验证了数学模型的正确性及仿真输出结果能准确的反映实际系统的性能,该部分主要工作如下:(1)研究了利用数字化匹配滤波器组进行伪码捕获的方法,通过对其数学模型和参数设计进行分析,建立了捕获环路仿真模块,进行了在高斯白噪声下检测概率仿真实验,并与理论分析结果进行了比较。(2)研究了利用超前/滞后非相干延迟锁定环进行伪码跟踪的方法以及科斯塔斯环进行载波同步跟踪的方法,分别对其数学模型和参数设计进行了分析,建立了跟踪环路仿真模块,进行了仿真实验,并与理论分析结果进行了比较。第二部分研究了FH/DS混合扩频通信系统的几种抗干扰技术,通过仿真实验研究了各种抗干扰技术的性能,该部分主要工作如下:(1)设计了基于频域FFT的窄带干扰检测与抑制算法,建立了抗干扰仿真模块,通过仿真实验验证了基于频域FFT的窄带干扰检测与抑制算法的有效性。(2)设计了基于分数域FRFT的宽带线性调频干扰检测与抑制算法,建立了抗干扰仿真模块,通过仿真实验验证了基于分数域FRFT的宽带线性调频干扰检测与抑制算法的正确性。更多还原

【Abstract】 As a new communication mode, the spread spectrum communications are widely used in military communications、satellite communications、mobile communications and C 3I (Command, Control, Communications & Intelligence) system, because of its well multiaddress access, low probability intercept, the excellent performance of anti-interference and secrecy. So the study of a hybrid direct sequence frequency hopping(DS/FH) communication system and the techniques to reject the interference is very important in communication field.In this dissertation, a hybrid FH/DS system and its interference rejection and anti-jamming technologies are studied. The main work includes two parts: The study of the key technologies in a hybrid FH/DS system and the modeling and simulation of a hybrid FH/DS spread spectrum communication system; the design and simulation of interference rejection mode in a hybrid FH/DS system.In the first part the technique of PN sequence synchronization and carrier synchronization in digital receiver for hybrid FH/DS spread spectrum communication system are studied. The dissertation analyses its mathematical model and design of parameters, and finish its simulative model in simulink. Through the experiment, the dissertation testifies that the mathematical model is correct and simulative result can approximately reflect the performance of real system. The main work of this part is listed as following:(1) For PN sequence acquisition scheme, the dissertation studies the all digital matched filters acquisition scheme and its mathematical model and parameters, and designs simulative model for acquisition loop. Then the dissertation compares the theoretical analysis of the detection probability on white noise and its computer simulation result, and testifies validity of the simulative model.(2) The dissertation studies a noncoherent all digital delay lock loop suited for chip timing synchronization and costas loop for carrier recovery, analyses their mathematical model and parameters respectively, and designs simulative model for tracking loop. Then the dissertation compares the theoretical analysis and the computer simulation result, testifies validity of the simulative model.In the second part the dissertation designs several interference suppression technologies for FH/DS spread spectrum communication system. Through the experiment, the dissertation studies different interference suppression technologies’performance. The main work of this part is listed as following:(1) Design the algorithm used in determining and suppressing the narrowband interference, and the anti-jamming simulative model. Through the experiment, the dissertation testifies validity of the interference suppression algorithm.(2) Design the algorithm used in determining and suppressing the broadband linear FM interference, and the anti-jamming simulative model. Through the experiment, the dissertation testifies validity of the interference suppression algorithm.更多还原