基于毫米波雷达的频谱细化与校正

Spectrum Refinement and Correction Based on Millimeter Wave Radar

随着频谱资源的紧缺以及第五代通信技术的发展,毫米波与亚毫米波在卫星和雷达军用上成为技术重点,但也是由于毫米波的波长较短,所以在毫米波通信中,传输信号以毫米波为载体时容易受到外界噪声等因素的干扰和不同程度的衰减。信号的截断会产生能量泄漏,导致频谱发生畸变,虽然可以通过选择不同的窗函数对它们的影响进行抑制,但是由此造成的误差不容忽视。采用FFT变换计算频谱会产生栅栏效应,通过增加FFT的点数可以降低频率估计误差,进而提高线性调频探测系统的测量精度,减小栅栏效应的影响,但是增加FFT的变换点数必然导致成倍增加变换的运算量,导致延时增加,系统的实时性变差。因此,在对信号做完FFT变换之后,需要对得到的离散频谱进行一系列频谱细化和频率校正操作,从而达到减小误差提高分析精度的目的。

With the shortage of spectrum resources and the development of the fifth-generation communication technology,millimeter wave and submillimeter wave have become the technical focus in satellite and radar military applications.But it is also because of the short wavelength of millimeter wave,so in millimeter wave communication,the transmission signal is vulnerable to external noise and other factors and attenuations of different degrees when the millimeter wave as the carrier.Signal truncation will generate energy leakage and lead to spectrum distortion.Although their influence can be suppressed by selecting different window functions,the resulting errors cannot be ignored.Spectrum is obtained by using the FFT transform produces the fence effect,by adding points FFT can lower frequency estimation error,thereby improving the measuring accuracy of linear frequency modulation detection system,reduce the effect of the fence,but adding points FFT transformation inevitably leads to multiply transformation of computation,lead to increased latency,poor real-time performance of the system.Therefore,after the FFT transformation of the signal,a series of frequency refinement and frequency correction operations are needed for the obtained discrete spectrum,so as to achieve the purpose of reducing errors and improving the accuracy of analysis.