Synchronization method based on PN sequence in NAVDAT (Navigational Data)

The invention discloses a synchronization method based on a PN sequence in NAVDAT (Navigational Data). The method comprises following steps of (1), inserting the known PN sequences of a receiving end on the subcarriers of OFDM symbols as synchronization headers, at a NAVDAT sending end; (2), carrying out time synchronization by using a method correlated to local PN sequences, at a NAVDAT sending end; (3), using the ratios of current correlation values and intra-window correlation values as the measurement standards of correlation peaks; (4), finishing frequency synchronization through adoption of a same PN sequence frequency domain conjugate correlation method. According to the method, the time synchronization is carried out by using the PN sequences with synchronous frequencies fully, the time synchronization accuracy is improved, the ratios of the current correlation values and the average value of the intra-window correlation values are taken as the measurement standards of the correlation peaks, the influences of the amplitude of the actually received signals on the correlation peak values are eliminated, the frequency synchronization is finished by using the frequency domain conjugate correlation method, and the synchronization method provided by the invention has the advantages of simple realization, low calculation complexity and high synchronization accuracy.