新型FSK/PSK复合调制信号研究

【作者】 唐海；

【导师】 周先敏；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2002， 硕士

【摘要】 本论文结合国家‘九五’军事预研项目‘低截获概率雷达波形研究’展开，并有扩展。在分析已有的频移键控(FSK)和相移键控(PSK)调制的基础上，给出一种新型复合调制雷达信号波形的设计方法。设计的目的是将雷达发射的有限能量尽可能的优化分配到设计信号的频谱带宽内包含目标特征信息的重要频点处。 该方法是同时进行频率和相位的数字调制(FSK、PSK)，设计伪随机FSK／PSK信号。频率编码为不均匀分布，由雷达观测目标的频谱信息提取出概率密度函数决定频率编码序列的分布，反映目标的信息；相位编码为二元的伪随机序列，采取均匀的二相编码，消减同频脉冲带来的过高的相关函数的旁瓣。较其它复合调制信号，该伪随机FSK／PSK信号的显著特点是随机性和谱适应性。每个发射周期设计的信号满足一定的统计规律，频域统计特性完全一致，时域波形则完全不同，信号本身具有随机性；其次，跳频序列(FSK)具有反映任意分布的能力，使信号具有谱适应性。论文中对这种信号进行了理论分析，讨论了作为雷达信号应用的基本特性(频谱特性、模糊函数、距离分辨率、速度分辨率、多普勒容限等)；研究这种满足一定统计规律的信号的相关特性；讨论了利用雷达目标冲激响应建模的原理，为这种调制方式的频谱编码分布的信息提取提供理论依据，例证了从理想的多散射中心方式建模的目标回波信号中进行目标信息提取；给出了这种伪随机FSK／PSK信号相关接收的两种应用；最后，利用Matlab进行在无噪声理想情况下的自相关接收和互相关接收的计算分析。 从研究中可以得出，这种设计方式的信号具有大BT，高分辨特性、低截获特性、抗电子干扰特性、随机性。在目标探测方面，由于信号本身具有匹配任意频谱的能力，较一般雷达信号有更强的探测能力；由于设计的波形的跳频序列的分布体现了目标的信息和这种波形的高的距离分辨特性，作为目标识别和成像也具有重要的意义。更多还原

【Abstract】 In the dissertation that extends based on the military item of ’95’ advance research, a novel multi-modulation technique designing radar signal waveform is introduced on the base of the analysis of the haven achieved frequency shift keying (FSK) and phase shift keying (PSK). The object of designing is to concentrated the signal energy in spectral location of most importance that contains target’s information within the broad spread spectrum bandwidth.This method digitally modulates frequency and phase in the same time and produces pseudo-random FSK/PSK signal. Frequency code is not uniformity distribution and keeps to a probability distribution function defined by the spectral characteristics of the target of interest. The phase code is equally duality pseudo-random sequence and used to reduced the sidelobes of the signal correlation function. Contrast to others hybrid waveforms, the mostly characteristics of this signal is the randomicity and the adaptability of spectral. At every time of transmitting it, the signal certainly satisfy one statistic rule that the amplitude of spectrum is sameness and the time waveform is entirely unlikeness. It shows randomicity. The FSK sequence has the ability to represent arbitrary distribution of spectrum and therefore has the adaptability of spectral. In the dissertation, the signal is analyzed theoretically, studying its specialitis used in radar(frequency spectral, ambiguity function range resolution, volcity resolution and Doppler toleration); studying the correlation speciality the signal with one statistic rule; studying the basis of modeling using radar impulse response and provides the ground of frequency code; explaining target’pole information estimation through a example of a model of multi-scatter centers; giving the two applications of the correlation receiver; analyzing the result of computering correlation and cross-correlation ceveiver using Matlab in without noisiness.Then come to the conclusion that the signal has the efficiency of big BT, high resolution, low probability of intercept, anti-jam and randomicity . The adaptability of spectral allows the radar to more effectively detect or track the target. Additionally, itsfrequency distribution showing the information of the target and its waveform having high range resolution make it important sense to target recognition and imaging.更多还原