Burst direct sequence spread spectrum system and pseudo code synchronization method of burst direct sequence spread spectrum waveform thereof

Abstract

The invention discloses a burst direct sequence spread spectrum system and a pseudo code synchronization method of a burst direct sequence spread spectrum waveform thereof. By adoption of the burst direct sequence spread spectrum system disclosed by the invention, the capturing, tracking and convergence times of a burst direct sequence spread spectrum signal can be greatly shortened, and the frequency offset estimation precision is relatively high. The burst direct sequence spread spectrum system disclosed by the invention is realized by the following technical scheme: in a signal modulation system, a specific segment of lead data is added in front of user data after scrambling and channel encoding are carried out on the user data for accomplishing signal capture and synchronization; and in a signal demodulation system, pseudo code phase capture and carrier frequency offset capture are carried out on a digital baseband signal to accomplish signal capture, coarse pseudo code phase synchronization and coarse frequency offset compensation with a coarse synchronizer, precise signal synchronization of a coarse synchronization signal is separately accomplished by pseudo code phase and carrier phase synchronization loops, identification information and a starting position of a user data segment are determined from a precise synchronization signal by a frame synchronizer, and the user data are restored by channel decoding and descrambling.

Description

technical field [0001] The invention relates to a high dynamic weak target acquisition and tracking method based on a direct spread signal waveform in a burst mode, especially in a high dynamic scene where a transceiver moves relative to each other at a high speed, aiming at aligning the Doppler frequency deviation with the clock deviation The influence of the spread signal, the method of quickly capturing the pseudocode phase and carrier phase and synchronously tracking the signal is completed. Background technique [0002] Spread spectrum technology is a technology widely used in the field of communication. Due to the characteristics of strong anti-interference ability, low intercept probability, anti-multipath and good confidentiality, spread spectrum communication has been widely used in satellite communication and mobile communication systems, among which the direct sequence spread spectrum system is the most widely used. During the use of spread spectrum equipment, wh...

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Problems solved by technology

[0007] The purpose of the present invention is to address the shortcomings of the above-mentioned prior art, especially the problem that the burst direct spread system cannot balance the accuracy and range of download wave estimation at extremely low signal-to-noise ratios, and to provide a method with less resource occupation and short capture time. It is suitable for the burst direct spread system and its direct spread waveform fast acquisition and signal synchronous tracking method under high dynamic conditions, so as to significantly shorten the convergence time and have high frequency offset estimation accuracy

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