Flash judgment and fast recapture device and method for satellite communication signals

Abstract

The invention provides a flash judgment and fast recapture device for satellite communication signals, including a DDC, a correlator, a loss-of-lock judgment module and a loss-of-lock recapture module. The device is characterized in that the DDC is a digital down converter and is used for digital down conversion of signals, the output signals of the DDC are divided into two channels, one channel of signals is input to the correlator for correlation judgment, signals r(n) are directly sent to the loss-of-lock recapture module through the other channel, and the loss-of-lock recapture module willdirectly capture signals if the system is in a state of signal capture success; the correlator is used for extracting information from interference and noise by making use of the correlation characteristics of address codes and outputting a correlation value R(m); the loss-of-lock judgment module is used for judging whether the extracted information loses lock; and the loss-of-lock recapture module resets the code phase of the correlator and restarts signal capture if the extracted information is judged to lose lock. The device has the advantages of high probability of flash detection, low probability of flash false alarm and short recapture time after flash.

Description

technical field [0001] The invention provides a flash judgment and fast recapture method for satellite communication signals, the method provides a flash judgment method and a fast recapture method for the satellite signal flash problem, and can be applied to receivers, measurement and control responses Machine signal capture. Background technique [0002] After the receiver receives the signal, it must first reproduce the PRN (pseudo random noise) code transmitted by the satellite that will be captured by the receiver, and then it must move the phase of the reproduced code generated by the receiver itself until it is in line with the PRN of the satellite. until the code is correlated. Correlation is greatest when the phase of the receiver's reproduced code matches the phase of the incoming satellite code. There is minimal correlation when the phase of the recurring code is offset from the phase of the incoming satellite code by more than 1 chip on either side. This is ho...

AI Technical Summary

Problems solved by technology

[0005] In actual satellite-to-ground communication, factors such as ionospheric jitter and sudden changes in the atmosphere will cause the receiving signal of the receiver to flicker, and the signal interruption time may reach several ms to tens of ms. At this time, the receiver tracks the output of the loop correlator The result is bound to be a wrong value. The frequency discrimination and phase discrimination errors based on the wrong correlation results will cause the loop to deviate. The longer the interruption time, the greater the deviation

Moreover, after the signal returns to normal, it is difficult for the receiver to keep tracking the signal and lose lock

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