Processing method of automatically calibrating sum-and-difference passage spread spectrum code phase to coincidence

Abstract

The invention provides a processing method of automatically calibrating a sum-and-difference passage spread spectrum code phase to coincidence in a spread spectrum double-passage system tracking receiving machine. The method can be used for effectively reducing the dispreading loss of difference path signals to obtain the maximum angle error detection sensitivity. The invention is realized through the following technical scheme: in a digital signal processing module in a programmable gate array chip FPGA, a spread spectrum code recovered out from a sum path through a lock phase ring changes the delay quantity of the sum path spread spectrum code phase through two stages of memories (FIFO1 and FIFO2) controlled by clocks at different speed rates; and in a digital processor chip DSP, the logic control program of the whole phase calibration process can be designed to be used for receiving phase calibration commands sent by application software and controlling the reading and writing delay quantity changing the FIFO1 and the FIFO2, the calibration flow process of the spread spectrum code phase is automatically organized to be completed, and the sum-and-difference passage spread spectrum code phase is calibrated to coincidence.

Description

technical field [0001] The invention relates to a processing method for aligning the phase calibration of the spread spectrum code of the difference channel in a dual-channel spread spectrum system tracking receiver. Background technique [0002] At present, in the field of aerospace measurement and control in my country, the measurement and control network of the spread spectrum measurement and control system has just begun to be built, but relatively high requirements are put forward for the normal operation of the ground measurement and control equipment under the condition of low signal-to-noise ratio. The dual-channel tracking receiver of the spread spectrum measurement and control system in the prior art usually uses the spread spectrum code recovered from the sum channel to directly complete the despreading of the differential channel signal after the sum channel signal spreading code and carrier phase are locked, and the differential channel signal is recovered. Afte...

AI Technical Summary

Problems solved by technology

In such a case, if the spreading codes of the two channels are not calibrated and the phases are consistent, the sensitivity of angle error detection will be lost and the despreading loss of the differential signal will be reduced, which will affect the antenna tracking under low SNR conditions. The impact on the tracking accuracy of the target is very large. In severe cases, the normal demodulation of the angle error signal cannot even be achieved, resulting in the antenna being unable to achieve self-tracking of the target aircraft.

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