Pseudo code and Doppler combined capturing method for direct sequence spread spectrum signal under high dynamic

Abstract

The invention aims to solve the main problem of finding a pseudo code phase difference-Doppler frequency offset two-dimensional joint capture method of a direct sequence spread spectrum DPSK signal under high dynamic, and realizing capture of the direct sequence spread spectrum DPSK signal under large Doppler frequency offset. The method comprises the following steps: firstly, carrying out down-conversion processing on a received intermediate frequency direct sequence spread spectrum DPSK signal through a carrier; sending the received signal and the local pseudo code into a delayer for delay correlation processing, obtaining a Doppler frequency offset estimation value according to the corrected correlation peak position of the signal, and correcting the carrier by using the Doppler frequency offset value; carrying out down-conversion processing on the direct sequence spread spectrum DPSK signal by using the corrected carrier wave; and finally, correlating the multiple paths of continuous phase local pseudo codes with the Doppler compensated intermediate frequency direct sequence spread spectrum DPSK signal by adopting a code phase compression method to obtain a pseudo code estimated value. According to the invention, the capturing of the direct sequence spread spectrum DPSK signal under high dynamic can be realized, the joint estimation of the pseudo code phase and the Dopplerfrequency offset is completed, the Doppler frequency offset estimation error performance is small, the pseudo code phase capturing performance is good, the capturing time is short, and therefore it isguaranteed that good coarse synchronization is achieved before a received signal enters a signal tracking processing module, the complexity is lower, and a higher practical value is achieved.

Description

technical field [0001] The invention belongs to the technical field of digital communication, relates to intermediate frequency all-digital reception and pseudo-code and Doppler frequency offset capture of a spread spectrum communication system, and is a pseudo-code phase-Doppler frequency offset of a direct spread DPSK signal under high dynamics. Dimension union capture method. Background technique [0002] Pseudo-codes have the characteristics of anti-jamming ability, strong anti-fading ability, low interception rate, and good concealment, and are widely used in many fields, so it is very important to study the capture of pseudo-codes. The traditional pseudo-code capture methods include sliding correlation method and matched filter method, and there is a contradiction between capture speed and implementation complexity. At the same time, in a high dynamic environment, there is usually a high radial velocity between the receiver and the transmitter, which makes the receive...

AI Technical Summary

Problems solved by technology

However, in the prior art, there is no method that can well adapt to the high dynamic environment and achieve a better capture effect, which makes the performance of the direct spread DPSK signal all-digital receiver poor.

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