Modified smoothed pseudo Wigner-Ville distribution-based (MSPWVD-based) blind estimation method for pseudo code sequence of pseudo-random Bi-phase code-linear frequency modulation (PRBC-LFM) composite signal

Abstract

The invention asks for protecting a modified smoothed pseudo Wigner-Ville distribution-based (MSPWVD-based) blind estimation method for a pseudo code sequence of a pseudo-random Bi-phase code-linear frequency modulation (PRBC-LFM) composite signal and belongs to the field of signal processing. According to the method, time-frequency analysis is performed on the PRBC-LFM composite signal by adopting modified smoothed pseudo Wigner-Ville distribution (MSPWVD), and thereby, the time-frequency concentration is enhanced while the cross-term interference of the signal is effectively reduced, and the precision of estimating the pseudo-noise (PN) code sequence of the PRBC-LFM composite signal is increased. Firstly, the minimum section of the MSPWVD time-frequency diagram of the signal is obtained from the MSPWVD time-frequency diagram of the signal; the phase jump site of an estimated pseudo code is obtained through detecting the peak position in the minimum section, and finally, the estimation on the original sequence or the antitone sequence of the PN code of the signal is obtained. Meanwhile, by combining with an MSPWVD-Hough transformation and subspace decomposition (singular value decomposition-SVD) method, the influences of cross terms are further reduced and the influence of the noise is further restrained. According to the method, the PN code sequence can be accurately estimated at low signal to noise ratio to successfully obtain the estimation on the parameter of the PN code of the PRBC-LFM composite signal, and thereby, the capacity of monitoring, managing, detecting and disturbing the PRBC-LFM composite signal and designing a related new-system system is improved. The MSPWVD-based blind estimation method for the pseudo code sequence of the PRBC-LFM composite signal has a wide application prospect.

Description

technical field [0001] The invention relates to the field of signal processing, in particular to a method for blindly estimating pseudo code (PN code) sequence of pseudo code phase modulation and linear frequency modulation (PRBC-LFM) composite signal based on modified smooth Wigner-Ville distribution (MSPWVD). Background technique [0002] Due to the increasingly harsh working environment faced by complex modulated radio signals, the ability to resist interference has become a focus of radio signal research. Among them, the anti-jamming of the PRBC-LFM composite system is the focus and difficulty of research at home and abroad. The PRBC-LFM composite system signal has the characteristics of pseudo-random code and line frequency modulation signal, has good distance cut-off characteristics, strong anti-interference and ranging capabilities, and has become one of the important development directions in the radio signal working system. The PRBC-LFM composite signal can be rega...

AI Technical Summary

Problems solved by technology

[0020] Aiming at the above-mentioned technical problems existing in the prior art, the present invention proposes a method for blindly estimating the PN code sequence of the PRBC-LFM composite signal, which solves the problem of blind estimation of the PN code sequence of the PRBC-LFM composite signal, and overcomes the traditional method in reducing the signal cross term. At the same time, it reduces the influence of noise on the pseudo-code sequence estimation, thereby improving the accuracy of the blind estimation of the PN code sequence of the PRBC-LFM composite signal

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