Binary offset carrier signal tracking loop

Abstract

The invention discloses a binary offset carrier signal tracking loop, which comprises a correlator module, a phase discriminator unit and a filter unit. The correlator module is used for performing demodulation and despread processing on the input intermediate frequency BOC signals, and acquiring multi-path correlation values IIP, IIE, IIL, IQP, IQE, IQL and QIP between local signals and the intermediate frequency BOC signals; the phase discriminator unit is used for detecting the tracking error theta of the carrier phase and the subcarrier phase and measuring the tracking error tau of the spreading codes; and the filter unit is used for performing noise reduction and smoothing on the phase demodulation result, converting the output tracking error into corresponding frequency control words, correspondingly feeding the frequency control words back to the correlator module, tracking the input intermediate frequency BOC signals, and closing the tracking loop. The binary offset carrier signal tracking loop realizes the split tracking of the subcarrier and spreading codes, eliminates the tracking fuzziness of the BOC signals, reduces the requirement on the acquisition precision, improves the tracking performance of weak signals, widens the dynamic range of the loop, and improves the tracking stability of the BOC signals by using the periodicity of the subcarrier.

Description

technical field [0001] The invention belongs to the technical field of GNSS signal processing, and in particular relates to a binary offset carrier signal tracking loop. Background technique [0002] The satellite navigation signals of the new generation of GPS system, Galileo system and China's BD2 system will generally adopt binary offset carrier (BOC) modulation technology. Compared with the traditional BPSK modulation method, the BOC modulation method has the advantages of improving the utilization of the navigation frequency band, suppressing signal multipath errors, reducing signal coherence loss, improving pseudo-range measurement accuracy, and enhancing signal anti-interference performance. However, due to the multi-peak characteristic of the autocorrelation function of the BOC signal, the tracking loop may be wrongly locked on the winger, that is, the so-called "false lock" phenomenon (tracking ambiguity) occurs. In order to eliminate the ambiguity of BOC signal tr...

AI Technical Summary

Problems solved by technology

However, in practice the spacing of the correlation peaks increases slightly as the winger moves away from the main peak

[0007] (3) The anti-multipath performance of the peak jump method is poor

However, the DET algorithm does not make full use of the periodicity of the subcarrier, so the tracking stability for weak signals is poor

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