Non-cooperative Receiving Method for Long Code Spread Spectrum Signals of Linear Shift Register Sequence

Non-cooperative reception of Direct Sequence Spread Spectrum (DSSS) signals is one of the important tasks in the fields of electromagnetic spectrum monitoring, cognitive radio, and communication reconnaissance. In the current application, the reception of DSSS signals with periodic short codes is typically completed, and data code streams are obtained. However, there is a lack of effective non-cooperative reception methods for aperiodic long code spread spectrum signals. To address this problem, for DSSS signals using aperiodic long code sequences generated by linear shift registers, the constant rank property of the shift construction matrix of the sequence in the Galois field is utilized. We estimate the generator polynomial corresponding to the linear shift register by solving system equations in the Galois field, so as to recover the corresponding long code sequence. The signal despreading and demodulation are completed, and finally the information code stream carried by the signal can be obtained. The correctness and effectiveness of the method are verified through simulations. It provides an important reference for the application of non-cooperative reception of aperiodic long code spread spectrum signals.