Coherent Combining and Long Coherent Integration for BOC Signal Acquisition under Strong Interference

Abstract

Binary offset carrier (BOC) modulation was initially developed for GPS modernization, leading to the new military M-code BOC(10,5) at L1 and L2 (Barker et al., 2000;Betz, 1999). It was quickly adopted by other GNSS constellations and is now used in L1C D BOC(1,1), L1C P TMBOC(6,1,1/11), E1 A BOC(15,2.5), E1 B /E1 C CBOC(6,1,1/11), E6 A BOC(10,5), E5 AltBOC(15,10), and B1A BOC(14,2), B1C D BOC(1,1), B1C P QMBOC(6,1,4/33), B2a and B2b AltBOC(15,10), and B3A BOC(15,2.5), among others. The split-spectrum offered by BOC modulation was originally sought for its easy sharing of the crowded spectrum with the legacy binary phase shift keying (BPSK) signals that occupy the respective band centers. It turns out that the split-spectrum possesses a larger Gabor bandwidth, producing better ranging performance in terms of accuracy and multipath (Betz, 2015;Pany, 2010).The acquisition and tracking of a general BOC signal encounter the issue of multiple peak ambiguity (Gusi et al., 2016) even though it is less of a problem for multiplexed BOC (MBOC) signals due to low subcarrier rate (Pany, 2020). Many

A Baseband MLE for Snapshot GNSS Receiver Using Super-Long-Coherent Correlation in a Fractional Fourier Domain

“…Considering the measurements in the proposed MLE from Equations ( 15)-( 24), the estimate accuracy may be highly constrained. Moreover, there is no compensation for the long correlation power loss resulting from code grid migration error at the current stage of this work (Yang et al, 2022) or the code Doppler rate, which are two factors that could affect the sensitivity. These factors will be considered in our future work.…”

“…For example, the GFZ German Research Centre for Geosciences built a service that offers navigation data information for GPS L1 C/A (Beyerle et al, 2009). This state-of-the-art technique uses a combined S-LCI method and has been proposed to mitigate strong interference in the GNSS signal acquisition (Yang et al, 2022). While this work leverages a phase rotation method to compensate for the carrier phase migration generated by the frequency error in the S-LCI, it cannot correct the phase error due to the Doppler rate.…”

Overview of multipath mitigation technology in global navigation satellite system

“…According to the analysis and simulation of the power spectral density and auto-correlation function of the BOC It can be seen from the figure that the power spectrum of the BOC signal is far away from the center frequency of the original BPSK, which realizes the spectrum sharing of the signal. Secondly, the narrower main peak of the auto-correlation function also enables the BOC signal to have higher precision code tracking performance and better multipath mitigation performance [38]. However, higher requirements are placed on the receiver acquisition and tracking due to the increase in the number of peaks of the auto-correlation function.…”