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In the navigation data processing,the speed and accuracy of the frame synchronization processing plays an important role in system efficiency and signal analysis.Unlike other navigation message which synchronized using a fixed sequence,In GPS L1C CNAV‐2 navigation message,and the synchronization code uses the BCH (51,8) code based TOI(Time of Interval) and is no longer fixed binary sequence.The TOI,in GPS L1C CNAV‐2 navigation message,is the 18 seconds count value in every two hours while indicated by ITOW(Interval Time of Week) and cyclically changes between 0 and 399.Thus,the BCH coding generated by the TOI is circular.Thus,the synchronization algorithm used in fixed binary sequence does not work anymore.Beside,circularity makes us have to count maximum correlation in the two adjacent frames simultaneously and traversal 256 pairs of sequences at last in each detection,whichinfluence the speed of the frame detection and the real timeliness of receiver.To solve this problem,beginning with the shift registers whichgenerate synchronized code of GPS L1C CNAV‐2 navigation message,this paperanalysisthe three characteristics ofthe loop resistance,autocorrelation,and cross‐correlation.Then,the paper designs the fast adaptive synchronization algorithm for GPS L1C CNAV‐2 navigation message.In this synchronization algorithm,the first step is estimating the number of error bit in the front nine bit of 52 bit,an integral BCH coding.Then,filter and sort these possible pairs of sequences.When we count the maximum correlation in the two adjacent frames simultaneously,the pairs of sequences is detected based on the priority order.Thus,the fast adaptive synchronization algorithm makes the fast synchronization and low rate of false synchronization in different signal conditions.