Improving range precision of LFMCW radar by spectrums fusion of Multi-Section Co-Frequency sinusoids

For improving range precision of Liner Frequency Modulation Continuous Wave (LFMCW) radar, a frequency estimation algorithm based on spectrums fusion of Multi-Section Co-Frequency(MSCF) sinusoids is proposed. To avoid sampling Intermediate Frequency(IF) signals in irregular-areas, IF signals in regular-areas are converted into MSCF sinusoids by an easy discontinuous sampling method. Then Optimization Weighted-Accumulation(OW-A) spectrum is gained through weighted-accumulation spectrums of MSCF sinusoids by the weighted factor. Thirdly, the correlation spectrum is created by correlating OW-A spectrum and the accumulation spectrum of MSCF sinusoids. Consequently, exact frequency estimation of IF signals in regular-areas can be obtained through spectral peak searching of the correlation spectrum, and high precision range of LFMCW radar can be achieved. Simulation results demonstrate that frequency estimation Root Mean Square Error(RMSE) of the proposed algorithm is about 1/5 times as same as that of FFT+CZT method; the range precision of LFMCW radar based on the proposed algorithm can be below 1mm.