Method for capturing BOC (1, 1) modulation signal

The invention discloses a BOC (1, 1) modulation signal capturing method, which comprises the following steps: sampling an autocorrelation function with a certain sampling interval parameter to obtain five sampling values, forming a capturing pattern M by the energy values of the five sampling values, and in a'searching 'stage, deciding to continue searching detection or transition of a state to a'confirmation' stage according to the form of the capturing pattern M, and adjusting sampling points, so as to obtain a BOC (1, 1) modulation signal. In the confirmation stage, according to the form of the captured pattern M, determining to continue residence confirmation or transition of the state to the traction and search stages, and adjusting the sampling points; in the'traction 'stage, the maximum value in the five energy values is compared with a preset lock loss threshold T1, if the maximum value is smaller than the lock loss threshold, the state returns to the'search' stage, and if the frequency error (or the