Three-dimensional quick capturing method for hopping spreading code phase and carrier wave Doppler

Abstract

The invention discloses a three-dimensional quick capturing method for a hopping spreading code phase and a carrier wave Doppler. The method includes: firstly, obtaining a local frequency-hopping carrier wave through a frequency synthesizer by using a local frequency-hopping pattern, and performing de-hopping and low-pass filtering to received signals; then, performing figure automatic gain control to data acquired after low-pass filtering, and extracting the data according to a corresponding ratio, and reducing operation amount of subsequent processing; and finally, producing a local direct sequence codon to de-spread the extracted data, and then performing a first accumulation, and performing a second accumulation after accumulated data frequency-hopping phase rotates, performing FFT (fast fourier transform) to the accumulated data, and finding a maximum peak by comparison. A local hopping spreading code phase and a frequency value corresponding to the maximum peak are a hopping spreading code phase and a carrier wave Doppler of the received signals. By the aid of the method, quick and simultaneous capturing of the hopping and spreading code phase and the carrier wave Doppler of a DS / FH (direct sequence / frequency hopping) mixing spread spectrum system under a strong interference condition is realized, and the method is low in realization complexity degree and has a fine anti-interference performance.

Description

technical field [0001] The invention relates to a signal phase acquisition method, in particular to a DS / FH hybrid spread spectrum system hopping spread spectrum code phase and carrier Doppler three-dimensional rapid acquisition method, which belongs to the communication field. Background technique [0002] Hopping spread spectrum code phase and carrier Doppler acquisition is a key technology of DS / FH (Direct Sequence / Frequency Hopping, Direct Spread / Frequency Hopping) hybrid spread spectrum system, and its capture performance and complexity directly determine The anti-interference ability and realizability of hybrid spread spectrum system are improved. [0003] Traditional spread spectrum acquisition generally adopts a two-dimensional acquisition method based on FFT (Fast Fourier Transform), that is, the signal is acquired in two dimensions of direct spread code phase and carrier Doppler. However, because the DS / FH hybrid spread spectrum system needs to search in the three...

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Problems solved by technology

However, since the DS / FH hybrid spread spectrum system needs to search in the three dimensions of frequency hopping code phase, direct spread code phase and carrier Doppler, the traditional method cannot complete the capture of the DS / FH hybrid spread spectrum system

[0004] The existing three-dimensional acquisition method for DS / FH hybrid spread spectrum system needs to first complete the search for the frequency-hopping code phase within one hop, and then use the two-dimensional acquisition method to capture the direct spread code phase and carrier Doppler, which limits The cumulative length of direct spread correlation of the system must not exceed the interval of one hop, resulting in low anti-interference ability of the system when the frequency hopping rate is high

Therefore, this method is not suitable for the requirements of the system for fast frequency hopping and anti-interference ability

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