雷达回波序列插零对信号频域特性的影响

针对信号不满足Nyquist采样定理出现频谱混叠时,在雷达回波中表现为目标多普勒频率混叠或速度模糊的问题,研究了雷达回波序列插零对原信号频域特性的影响.首先从理论上分析并证明了对离散时间序列进行插零可解决频谱混叠的问题;其次分析了由于插零法会导致增加新的频率成分,并且增加的频率成分与插值点数、采样频率以及信号中原有的真...

Influence of zero interpolation of radar echo series on signal frequency domain characteristics

In order to solve the problem of target Doppler frequency aliasing or velocity ambiguity in radar echo when the signal does not meet the Nyquist sampling theorem,this paper studies the influence of zero interpolation of radar echo series on the frequency domain characteristics of the original signal.Firstly,the paper makes a theoretical analysis and proves that the problem of frequency spectrum aliasing can be solved by inserting zeros into discrete time series.Secondly,the paper makes an analysis that new frequency components will be generated due to the method of inserting zeros,and the added frequency components are related to the number of interpolation points,sampling frequency and the original real frequency in the signal.Finally,according to the theoretical analysis,the paper gives the general conclusion of signal amplitude and frequency variation after zero interpolation of discrete time series.Both the theoretical analysis and simulation results show that the conclusions of the research are correct,which provides a theoretical support for the real frequency estimation in the case of under-sampling or frequency spectrum aliasing in practical applications.