基于欠采样的宽带线性调频信号参数估计

基于中国余数定理解频率模糊和解线调方法,提出一种无模糊欠采样的宽带线性调频信号的调频斜率和初始频率的估计算法.首先,欠采样宽带线性调频信号与其两路不同延迟共轭相乘,根据两路输出信号的单频特性,利用FFT、谱峰检测(PSD)和中国余数定理进行宽带线性调频信号的调制斜率无模糊估计;其次,根据估计的调制斜率数字合成无载波的线性调频信号对另外两路不同延迟的欠采样宽带线性调频信号解线调处理,利用类似方法进行宽带线性调频信号的初始频率无模糊估计.利用频谱细化技术,参数估计精度可进一步提高.计算机仿真证实了算法的有效性.

An algorithm for estimation of wideband LFM signal parameters based on subsampling

Based on the remainder theorem and direct dechirp operation,an algorithm for estimation of chirp rate and initial frequency of the subsampling wideband LFM signal unambiguously is presented.Since the subsampling wideband LFM signal and its two difference delay visions conjugation product are all single tones,the chirp rate is estimated unambiguously by FFT and spectrum peak search detection(PSD)and remainder theorem.Then using the estimated chirp rate,the dechirp operations are finished by the digital synthesis no carrier chirp signal for another two difference delay subsampling wideband LFM signals,and the initial frequency of the subsampling wideband LFM signal can be estimated unambiguously by the similar methods.Moreover,with spectral zooming,the estimated parameter precision can be improved.Simulation proves the validity of the algorithm.