A Spread Spectrum Method Against Spoofing

Abstract

The invention discloses a cheating and interference resistant spectrum spreading method, and mainly solves the problems that the capability of resisting cheating and attack is low and the bit error rate of information under a low signal to noise ratio is high in the prior art. The method comprises that 1) a spreading level N and a spreading code set P are set initially; 2) an emission end spreadsthe spectrum of source information, inserts position information of a 0 level of spreading code in the spreading code set P is a 0 level of spreading signal randomly, and emits the inserted signal; 3)the emission end spreads an index position of a last level of spreading code in the spreading signal, inserts position information of the spreading code used by the present level in the spreading code set P into the present level of spreading signal, and emits the inserted signal; and 4) a reception end carries out iterative dispreading on the spreading signal, and obtains source information of the emission end. Via the method of the invention, the error rate under the low signal to noise ratio is lower, an attacker confronts with a larger search space during dispreading, the capability of resisting cheating attack is improved, and the method can be used for resisting cheating attack of a navigation system.

Description

technical field [0001] The invention belongs to the technical field of information processing, and further relates to a spread spectrum method for anti-spoofing interference, which can be used in satellite navigation systems. Background technique [0002] With the wide application of satellite navigation systems, the safety of navigation information has attracted more and more attention. The C / A code based on the gold sequence, as the navigation signal spreading code in the satellite navigation system, is open to the public. Due to the openness of the C / A code, it is easy for malicious attackers to obtain the spreading code used by the satellite to send signals. frequency sequence, and use it to forge a false signal and send it to the receiver, so that the receiver can obtain wrong navigation information, causing serious consequences. [0003] The patent "GPS navigation system spread spectrum sequence construction method" (application number: 200810227284.2, application pub...

AI Technical Summary

Problems solved by technology

[0007] The disadvantage of this method is that the construction method of this spread spectrum sequence can only effectively resist multipath, and has no resistance to the spoofing attacks existing in the GPS navigation system

The problem of this method is: because the sequence correlation is sensitive to noise, it is difficult to work reliably in the case of low signal-to-noise ratio, and the number of spreading sequences used in spreading each group of information is relatively small, which is easy to be seen by cheaters The probability is higher, and the performance against spoofing attacks is poor

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