Blind estimation for the period of Pseudo Noise code and the combination code in binary offset carrier signal

For the blind estimation problem of period of the PN (Pseudo Noise) code and the combination code (combination of spread spectrum sequence and subcarrier sequence) in BOC (Binary Offset Carrier) signal with the residual carrier in the low SNR (signal-to-noise ratio), the method which combines the reprocessing of the power spectral density with matrix decomposition is developed. Firstly, the reprocessing of the power spectral density of BOC signal with the residual carrier is calculated. There are sharp pulses appearing at the integer times of period of the pseudo code. Detecting distance of these peaks can estimate the period of the pseudo code. Then the sampling signals are sectioned according to the period of the pseudo code to get the data vector. Finally the correlation matrixes of the data vector and matrix decomposition of the correlation matrix are calculated. The combined code sequence can be estimated with the two largest singular values and their vector. The simulation results show that, the method can be accurate estimation performance for the signal with larger residual carrier at the lower SNR.