The invention relates to a table look-up method-based Beidou
signal high-precision capturing method and belongs to the technical field of
satellite navigation. The method comprises the following steps that: step 1,
satellite signal pseudo codes are stripped; step 2, FFT is performed on the signals; step 3, a threshold value is set; step 4, an FFT output main
peak value is compared with the threshold value, and if the FFT output main
peak value is higher than the threshold value, capture is successful, and captured
Doppler frequency shift is fd; step 5, an FFT output secondary
peak value is compared with the threshold value, and if the FFT output secondary peak value is higher than the threshold value and is adjacent to a main peak position,
Doppler frequency shift can be corrected, otherwise, fd is taken as a capture result; step 6, table look-up is performed with the ratio of an FFT output main peak to an FFT output secondary peak adopted as an address, so that a correction value fx is obtained; and step 7, a position relation between the main peak and the secondary peak is judged, if the secondary peak is on the left side of the main peak, corrected
Doppler frequency shift is fd-fx, otherwise, the corrected Doppler
frequency shift is fd+fx. The method is applied to a Deidou
signal software receiver and can effectively improve the capture precision of the Doppler
frequency shift under the condition that computational load is almost not increased.