摘要
现代雷达系统中对信号的复杂性和抗干扰性要求越来越高,使用复合系统代替简单系统成为了必然选择。本文提出了一种利用伪随机码对三角波线性调频信号的多个参数进行调制的发射信号体制,设计并实现了一种具有抗噪声调幅干扰性能的多参数复合调频探测系统。该系统在测距方面采用双路频谱细化高精度测距算法,在测速方面采用双路时域欠采样的测速算法。在抗干扰方面采用分数阶傅里叶变换法抑制噪声调幅式干扰,并通过频移键控解调法将接收信号的伪随机编码序列解调出来,再通过计算收发编码的相关特性进行判断目标是否到达定距范围,可有效识别和抵御信息型干扰。本系统能够在系统受到噪声调幅压制性干扰时,仍然能够实现正常的测距测速功能,且通过收发编码的相关特性实现定距功能,保证系统在定距范围外不会输出判决信号,能够极大提高探测系统的可靠性。
In modern radar system,the signal complexity and anti-interference are more and more demanding,so it is inevitable to use composite system instead of simple system.In this paper,a transmitting signal system using pseudorandom code to modulate multiple parameters of triangular wave linear FM signal is proposed.A multi-parameter compound FM detection system with anti-noise AM interference performance is designed and implemented.The system uses double channel spectrum thinning and high precision ranging algorithm in distance measurement and double channel time domain undersampling in speed measurement.In terms of anti-interference,fractional Fourier transform method is used to suppress noise amplitude-modulation interference,and the pseudo-random coding sequence of the received signal is demodulated by frequency-shift keying demodulation method,and then the relevant characteristics of the sending and receiving coding are calculated to judge whether the target reaches the range,which can effectively identify and resist information interference.This system can still realize the normal ranging and velocity measurement function when the system is subjected to noise amplitude-modulation suppression interference,and realize the range function through the relevant characteristics of sending and receiving coding,so as to ensure that the system will not output the decision signal outside the range of the range,which can greatly improve the reliability of the detection system.
作者
李勇强
张淑宁
陈思
LI Yong-qiang;ZHANG Shu-ning;CHEN Si(College of Electronic engineering and Optoelectronics Technology,Nanjing University of Science and Technology,Nanjing 210094 China)
出处
《微波学报》
CSCD
北大核心
2023年第S01期293-296,共4页
Journal of Microwaves
关键词
复合调频
分数阶傅里叶变换
相关特性
compound frequency modulation
fractional Fourier transform
related characteristics
