基于逐点扫描FFT法的跳频信号参数估计

Parameter Estimation of Frequency-hopping Signal Based on Spot Scanning FFT Method

针对时频分析方法估计跳频信号参数存在时频分辨率受限、交叉项干扰、实时性差等缺点,通过分析跳频信号的时频特性,提出一种新的跳频信号参数估计方法。该方法从未知信号的时域分析出发,采用逐点步进的方法进行多次FFT计算,通过分析其频谱特性判断跳频信号的跳变时刻,将跳频信号序列按跳频频率分割为多个单频率信号分量,最后再综合提取跳频信号的时频参数。仿真结果表明,该方法针对跳频参数的估计精度高,运算速度较快,且没有干扰频率。

In order to avoid the shortcomings such as the limited time-frequency resolution,redundant cross terms and poor real-time performance when the time-frequency distribution is used to estimate the parameters of frequency-hopping signal,by analyzing the time-frequency characteristics of frequency-hopping signal,a new method is presented for the parameter estimation. Firstly,the method takes the time domain analysis as a starting point and completes the FFT calculation many times based on the point-bypoint stepping. Secondly,it divides the frequency-hopping signal into some single-frequency signal components based on the hopping frequency. At last,it obtains the time-frequency parameters of the frequency-hopping signal. The experimental results show that the method is extremely effective for the parameter estimation of frequency-hopping signal and it has numerous advantages such as high estimation accuracy,fast operation and no interference frequency.