调频遥测信号载波频率的精确估计

传统调频遥测信号载波频率估计算法对输入信号降采样后直接进行快速傅里叶变换，实现方法虽然简单，但测量精度较差，无法适应高动态、低信噪比等复杂场景。为此，提出了一种调频遥测信号载波频率的精确估计算法。两并联补偿支路先分别采用正、负调频频率对输入信号进行频率预先补偿，低通滤波后完成降采样处理，削弱调频频率的频谱影响；频率搜索状态对采样数据进行载波多普勒变化率的频率补偿，经过快速傅里叶变换、非相干积分和频谱重心搜索完成频率解算，提高载波频率的检测性能。试验与分析表明，所提算法在高动态、低信噪比等复杂场景下可显著提高调频遥测信号载波频率的估测性能。

Accurate estimation of carrier frequency in FM telemetry signal

Traditional estimation algorithm for carrier frequency in frequency modulation(FM) telemetry signal directly uses the fast Fourier transform(FFT) after sampling the input signal.The method is simple but the precision is poor,and it is not applicable for the high dynamic and low signal-to-noise ratio(SNR) scenes.To solve the problem,an accurate estimation algorithm for carrier frequency in FM telemetry signal is proposed.To reduce the spectrum effect of FM frequency,double parallel branches use positive/negative FM frequency to prep-compensate the input signal,and obtain the sampled data after lowpass filtering.To improve the measuring performance of the carrier frequency,frequency search state uses the carrier Dopplor rate to compensate the sampled data and calculate the carrier frequency after FFT,the non-coherent integration and the frequency spectrum barycenter.The test and analysis results indicate that the algorithm can effectively improve the estimation performance of the carrier frequency in FM telemetry signal under high dynamic and low SNR conditions.