基于ZFFT的低信噪比无人机信号载频估计方法  

A Carrier Frequency Estimation Method for UAV Signal with Low SNR Based on ZFFT

作　　者：张丽宏[1] 郭福成[1] 张敏[1] Zhang Lihong;Guo Fucheng;Zhang Min(College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China)

机构地区：[1]国防科学技术大学电子科学与工程学院,长沙410073

出　　处：《遥测遥控》2017年第3期36-41,58,共7页Journal of Telemetry,Tracking and Command

摘　　要：针对远距离探测民用微型无人机信号时的低信噪比条件下高精度载波频率估计问题,提出基于Zoom-FFT(ZFFT)和二次插值(或Rife算法)的快速、精确估计改进算法。算法先利用FFT粗估信号频率,然后利用ZFFT算法对频谱细化,通过简化数字滤波器,采用积分求和的方式滤波,并与数据抽取相结合,同时实现滤波与抽取。最后,利用二次插值法(或Rife算法)对载频估计值作进一步修正。仿真结果表明,所提算法在低信噪比条件下估计精度和运算效率均有明显优势。Based on the Zoom-FFT and quadratic interpolation(or Rife algorithm),a fast and accurate carrier frequencyestimation method for UAV signal under low SNR conditions is proposed.This method utilizes FFT to get the coarseestimation of the carrier frequency,and then zooms the spectrum through the improved ZFFT,which simplifies the FIR filterand achieves filtering and decimation simultaneously by using an integrator.Finally,the quadratic interpolation method(orRife algorithm)is employed to further improve the accuracy of frequency estimation.The simulation results show that theproposed method can accurately estimate the carrier frequency of UAV signal in real-time,even under low SNR conditions.

关 键 词：频率估计 FFT 滤波 抽取 

分 类 号：TN971.1[电子电信—信号与信息处理]