基于多通道的跳频信号欠采样频率估计

为实现跳频信号频率跟踪估计，本文提出一种基于多通道的跳频信号欠采样频率估计方法。基于快速傅里叶变换（FFT），提出了一种3谱线方程的频率校正算法，提高了基于中国余数定理的频率估计方法对短序列信号的频率估计精度，与现有的两种基于离散傅里叶变换（DFT）的频率校正算法相比，序列补零数量灵活。给出了一种频率估计检错机制，可以提高算法可靠性。仿真结果表明，本文所提频率估计算法的精度优于现有算法，增加序列补零数量可进一步提高算法的估计精度和信噪比阈值，降低误差平台；检错机制在-23 dB至8 dB信噪比范围内的准确率高于95.5%。 

Under-sampled Frequency Estimation of Frequency Hopping Signals Based on Multi-channel

? ?To achieve frequency tracking estimation of Frequency-Hopping （FH） signal， a multi-channel-based frequency estimation method of FH under-sampling signal is proposed. A frequency correction algorithm based on fast Fourier transform （FFT） and 3-spectral line equation is proposed to increase frequency estimation accuracy of short sequence signal by using China remainder theorem （CRT）. Compared with the existing two frequency correction algorithms based on discrete Fourier transform （DFT）， the number of zero padding for a sequence in the proposed algorithm is flexible. And an error detection mechanism is proposed to judge whether the frequency estimation is correct， and the reliability of the algorithm is improved. Simulation experiments demonstrate that the frequency estimation precision of the proposed algorithm is better than that of the existing algorithms. The proposed algorithm can improve estimation precision and signal-to-noise ratio （SNR） threshold， and reduce error floor by increasing the number of zero padding. And the accuracy of error detection is higher than 95.5% in the range of -23 dB to 8 dB SNR.