CAJ | 학술논문

针对利用分数阶傅里叶变换（fractional Fourier transform ，FrFT ）进行干扰抑制时门限阈值设定的难题，为有效抑制DS/F H系统中的线性调频（line-ar frequency modulated ，LFM ）干扰，通过深入分析DS/FH和LFM 信号的FrFT性质，提出了一种新的LFM 干扰抑制算法，该算法充分利用FrFT 时频面坐标轴旋转性质，通过计算信号的不同阶次FrFT 并搜索其峰值，确定信号最优FrFT 阶次，完成对L FM 干扰信号的判别，最后采用频域陷波来抑制L FM 干扰。理论分析和仿真实验表明，该算法能够有效的剔除DS/F H系统中的L FM 干扰信号，不需要阈值门限设定，算法具有较好的稳健性和普适性。
침대이용분수계부리협변환（fractional Fourier transform ，FrFT ）진행간우억제시문한역치설정적난제，위유효억제DS/F H계통중적선성조빈（line-ar frequency modulated ，LFM ）간우，통과심입분석DS/FH화LFM 신호적FrFT성질，제출료일충신적LFM 간우억제산법，해산법충분이용FrFT 시빈면좌표축선전성질，통과계산신호적불동계차FrFT 병수색기봉치，학정신호최우FrFT 계차，완성대L FM 간우신호적판별，최후채용빈역함파래억제L FM 간우。이론분석화방진실험표명，해산법능구유효적척제DS/F H계통중적L FM 간우신호，불수요역치문한설정，산법구유교호적은건성화보괄성。
The threshold value setting is a challenge when interference suppression based on frac-tional Fourier transform(FrFT) .In order to suppress the linear frequency modulated (LFM)interfer-ence of DS/FH ,a novel algorithm to suppress the LFM interference is presented by analyzing the Fr-FT properties of DS/FH signal and LFM signal .The algorithm uses the properties that FrFT is the axis rotation in the time-frequency domain .First ,calculates each order FrFT of the signal ,and sear-ches for the peak value;secondly ,determines the optimal signal FrFT order by comparing each peak value;at last ,rules out LFM interference signals and uses the frequency domain notch filter to sup-press LFM interference .Theoretical analysis and simulation experiments show that this algorithm can effectively eliminate the LFM interference signal in the DS/FH system .It doesn't need to set the threshold and it also has better robustness and applicability .