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针对DS/FH(Direct Sequence/Frequency Hopping)混合扩频测控信号的快速捕获,经典的时域并行方法或频域并行方法已不能满足需求.为了进一步提高载波捕获精度,在PMF-FFT(Partial Match Filter-Fast Fourier Transform)算法基础上,提出了一种反馈式结构的时频域并行捕获算法,通过PMF-FFT算法粗估载波频偏,利用一种Quinn频率插值算法提高频偏估计精度,并使用估计结果调整本地载波,再次进行捕获.理论分析和仿真结果表明,该算法与PMF-FFT算法相比,提高了载波捕获精度,在大频偏低信噪比条件下增加了频率分析带宽、减少了平均捕获时间.
In order to further improve the accuracy of carrier acquisition, aiming at the fast acquisition of DS / FH (DS / FH) hybrid spread spectrum measurement and control signals, classical time domain parallel method or frequency domain parallel method can not meet the demand. Based on the Filter-Fast Fourier Transform (FFT-FFT) algorithm, a time-frequency domain parallel acquisition algorithm based on feedback structure is proposed. The carrier frequency offset is estimated by PMF-FFT algorithm and a Quinn frequency interpolation algorithm is used to improve the accuracy of frequency offset estimation. The estimation results adjust the local carrier and capture again.The theoretical analysis and simulation results show that compared with the PMF-FFT algorithm, this algorithm improves the carrier acquisition accuracy and increases the frequency analysis bandwidth under the conditions of large frequency and low SNR, Average capture time.