Pseudocode Blind Estimation Method for Direct Spread Signals with Multiple User Cycle Length and Short Codes

Abstract

The invention discloses a multi-user period long-short code DS signal pseudo code blindness estimation method; the method can model multi-user period long-short code DS signals with complex structures into a blind separation mode according to short spreading code and long scrambling code periods; the method comprises the following steps: using a Fast-ICA algorithm to separate mixed PN sequence segments of all users, and regrouping a fuzzy sequence; using the m sequence shift superposition property, and using a secondary delay phase multiplication to eliminate information code and spreading code influences; combining a cyclotomic coset theory to calculate signal third order correlation functions, thus determining the user mixed PN sequence and third order correlation peak point, using a matrix inclined resolving method to finish scrambling code estimation, and using a segment delay cross correlation method to finish the spreading code estimation after the signals are descrambled. The method can fully utilize the Fast-ICA algorithm and m sequence third order correlation characteristics, thus realizing blind estimation of two pseudo hatted codesof the multi-user period long-short code DS signals.

Description

technical field [0001] The invention belongs to the field of blind parameter estimation of direct sequence spread spectrum signals in communication countermeasures, and in particular relates to a method for estimating pseudo codes of multi-user periodic direct spread signals with short code spread spectrum and long code scrambled under non-cooperative communication. Background technique [0002] Direct Sequence Spread Spectrum (DSSS) is one of the main methods of spread spectrum communication technology. It has the advantages of strong anti-interference ability, good confidentiality, easy code division multiple access, etc., and has been widely used in military and civilian communications. According to the signal structure, DSSS signals can be divided into: short code direct spread signal, long code direct spread signal, short code spread spectrum and long code scrambling direct spread signal (referred to as long code direct spread signal). [0003] In communication counter...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the pseudo-code problem of the multi-user cycle length and short code direct spread signal that cannot be estimated in non-cooperative communication, and proposes a pseudo-random code blind estimation method based on the Fast-ICA algorithm and third-order correlation, thereby solving the Pseudo-code Estimation of Directly Spread Signals with Period Length and Short Codes

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