High-dynamic spread spectrum signal fast acquisition algorithm

Abstract

The invention discloses a high-dynamic spread spectrum signal fast capture algorithm, which comprises the following steps of: 1, capturing a signal R1, obtaining a signal Rt after delay time t, and performing autocorrelation operation on the signal R1 and the signal Rt of the delay time t based on an FFT Doppler offset estimation technology; 2, performing autocorrelation operation on the signal R1and the signal Rt of the delay time t of the signal R1 by using FFT, processing a result, and performing frequency offset analysis to obtain a Doppler frequency change rate. According to the algorithm disclosed in the invention, the Doppler frequency change rate is obtained through frequency offset analysis and calculation; the signal frequency offset reconstruction signal is compensated according to the Doppler frequency change rate k to obtain a signal without the frequency change rate; then, the pseudo code phase can be obtained only through one-time pseudo code capture, Doppler and pseudocode limiting serial stepping search is not needed, meanwhile, the capture threshold is compared and analyzed, the local carrier signal frequency and the pseudo code phase are modified according to the comparison result, and rapid capture of the high-dynamic spread spectrum signal is achieved.

Description

technical field [0001] The invention relates to the technical field of fast capture algorithms for spread spectrum signals, in particular to a fast capture algorithm for high dynamic spread spectrum signals. Background technique [0002] Spread spectrum communication technology is a method of information transmission. The frequency bandwidth occupied by the signal is much larger than the minimum bandwidth necessary for the information to be transmitted. The expansion of the frequency band is completed through an independent code sequence, which is realized by the method of coding and modulation. , has nothing to do with the transmitted information data; at the receiving end, the same code is used for related synchronous reception, despreading and recovery of the transmitted information data. At present, the application and service range of high-speed mobile objects such as aircraft and satellites are increasing, but they There are still problems in the acquisition of spread ...

AI Technical Summary

Problems solved by technology

[0002] Spread spectrum communication technology is a method of information transmission. The frequency bandwidth occupied by the signal is much larger than the minimum bandwidth necessary for the information to be transmitted. The expansion of the frequency band is completed through an independent code sequence, which is realized by the method of coding and modulation. , has nothing to do with the transmitted information data; at the receiving end, the same code is used for related synchronous reception, despreading and recovery of the transmitted information data. At present, the application and service range of high-speed mobile objects such as aircraft and satellites are increasing, but they There are still problems in the acquisition of spread spectrum signals under high dynamic conditions. Under high dynamic conditions, the carrier signal received by the receiver has a large Doppler frequency offset and a high Doppler change rate, which affects the effective acquisition speed of the signal. , the present invention provides a high dynamic spread spectrum signal fast acquisition algorithm