A high - resolution method for frequency measurement is strongly introduced in the paper , which is aim at detecting the frequency of regular and binary phase coding modulated pulse signals with high frequency precision . considering the popularity of linear frequency modulated ( lfm ) signal in electronic systems , this paper then referred a radon - stft arithmetic to calculate the carry frequency of lfm signal . both of these methods referred above are implemented in the signal if detection software 针对常规脉冲调制信号和脉内二相编码调制信号,本文提出一种高精度的数字化测频方法,以提高信号载频测量精度;线性调频信号作为一种典型的非平稳信号在各种领域应用十分广泛,但对其载频的数字化测量比较困难,本文利用图像处理中的radon变换与信号时频分析中的线性变换相结合的算法来完成对其载频的测量。
The pseudorandom codes have a good autocorrelation of double - values . in recent years , to solve the problems of anti - interference and the ambiguity of range and velocity , a lot of countries do much research to change the waveform of radar signal . the most important improve is to use symmetrical pulses to interrupt frequency modulated continuous wave ( fmpcw ) 早期的fmicw采用伪码序列截断,伪随机码具有良好的双值自相关特性,其中最常用的是m序列截断的fmicw 。近年来,为了解决抗干扰和测距、测速模糊问题,许多国家已对雷达信号波形的改进进行了研究。
Then to meet the problem of the separate between receiving and transmitting for single - station radar system in continuous wave principle , we introduced frequency modulated interrupted continuous wave ( fmicw ) . in early days , the pseudorandom codes were often used in fmicw . usually m - sequence is used to intertupt frequency modulated continuous wave 之后,为了解决连续波体制下,单站收发共址的雷达系统的收发隔离问题,又普遍采用了截断的线性调频连续波信号形式,叫做线性调频中断连续波信号( fmicw ) 。
Theoretical model of self - mixing interference in a linear frequency modulated laserdiode is presented by using the dynamic theory of semiconductor laser with weak external optical feedback . the characteristics of oscillation frequency shift and output power changes of the laser diode are analyzed by using the theoretical model . the absolute distance from front facet of laser diode to target can be found by measuring spectrum of output power of the laser diode 使用半导体激光器在弱反馈条件下的动力学理论,建立了线性调频半导体激光器的自混频干涉理论模型.基于该模型,分析了激光器振荡频率偏移与输出功率变化特性.通过测量激光器输出功率谱,可以得到激光器前端面与被测目标之间的距离