On-orbit navigation signal IQ phase consistency calibrating method

Abstract

The invention discloses an on-orbit navigation signal IQ phase consistency calibrating method, and belongs to the field of satellite navigation. The method includes the steps of conducting high-speed sampling for navigation radiofrequency signals, conducting quadrature demodulation for the intercepted navigation signal sampling data to obtain two roadbed band data, determining the pseudo-random code start point of a navigation signal I branch through circular correlation processing, extracting the Q-path baseband signals according to the pseudo-random code sheet interval with the half code sheet delayed than the start point, regenerating code elements of the navigation signal Q branch, conducting circular correlation respectively for the navigation signal data by using the local I branch pseudo-random code and regenerated Q branch code elements, respectively determining the pseudo-random code start points of the I branch and the Q branch in the navigation signals, and calculating the phase consistency of a navigation signaling channel in combination with sampling rate. The method is applied in a digital domain, the calibrate errors caused by self zero value error of reception equipment in conventional test equipment can be avoided, and the calibrating precision is high.

Description

technical field [0001] The invention relates to a calibration method for IQ phase consistency of on-orbit navigation signals, which belongs to the field of satellite navigation. Background technique [0002] The navigation signals broadcast by my country's in-orbit navigation satellites are QPSK modulated navigation signals. This QPSK navigation signal is divided into I branch short pseudo-random code signal and Q branch long pseudo random code signal. In many applications, in order to improve Q branch The acquisition speed of the signal often first receives the I branch signal, and the value obtained after the synthesis of the I branch signal phase value and the IQ phase difference calibration result is used as the initial value of the Q branch signal reception to accurately determine the IQ phase consistency of the satellite signal The result is very important to ensure the ranging accuracy of the long code signal navigation receiver and improve the acquisition speed. There...

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Problems solved by technology

The high-precision calibration algorithm requires a high sampling rate. The pseudo-random code of the I branch of the navigation signal is a short code. In the case of a high sampling rate, the calibration algorithm can complete the data processing of a period of pseudo-random code data samples, so this method is adopted method to calibrate the signal phase of the I branch, but the Q branch is a long-period pseudo-random code. Under the same sampling rate, the amount of data samples in one period is huge, and the proposed algorithm cannot satisfy the proposed algorithm. In addition, in the case of orbit, a random segment It is impossible to determine the long-code pseudo-random code corresponding to the time of sampling data, and the correlation peak cannot be extracted without knowing the pseudo-random code corresponding to the data segment. Therefore, this method cannot be used for IQ phase consistency of on-orbit navigation signals. sexual calibration

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