The Galileo E1 open service （OS） and the global positioning system （GPS） L1C are intending to use the multiplexed binary offset carrier （MBOC） modulation in E1/L1 band, including both pilot and data components. ...The Galileo E1 open service （OS） and the global positioning system （GPS） L1C are intending to use the multiplexed binary offset carrier （MBOC） modulation in E1/L1 band, including both pilot and data components. The impact of data and pilot codes cross-correlation on the distortion of the discriminator function （i.e., the S-curve） is investigated, when only the pilot （or data） components of MBOC signals are tracked. It is shown that the modulation schemes and the receiver configuration （e.g., the correlator spacing） strongly affect the S-curve bias. In this paper, two methods are proposed to optimize the data/pilot code pairs of Galileo E1 OS and GPS L1C. The optimization goal is to obtain the minimum average S-curve bias when tracking only the pilot components a the specific correlator spacing. Figures of merit, such as S-curve bias, correlation loss and code tracking variance have been adopted for analyzing and comparing the un-optimized and optimized code pairs. Simulation results show that the optimized data/pilot code pairs could significantly mitigate the intra-channel codes cross-correlation, and then improve the code tracking performance of MBOC signals.展开更多
Subcarrier modulated signals are widely used in the new generation of Global Navigation Satellite Systems(GNSS)to improve spectral compatibility and ranging accuracy.The unique structure of subcarrier modulated signal...Subcarrier modulated signals are widely used in the new generation of Global Navigation Satellite Systems(GNSS)to improve spectral compatibility and ranging accuracy.The unique structure of subcarrier modulated signals poses an ambiguity threat to acquisition and tracking,rendering traditional GNSS signal processing algorithms unsuitable.Designing unambiguous acquisition and tracking as well as observation extraction techniques for subcarrier modulated signals that can realize the high ranging accuracy potential while avoiding the ambiguity threat is a topic of common interest in both academia and industry.Numerous studies have addressed the ambiguity elimination problem of subcarrier modulated signals.However,to the best of our knowledge,no updated reviews on this topic reflecting recent advances in the field have been presented in the past few years.On the one hand,the unique composite subcarrier modulated signal structure in the B1 and B2 bands of the BeiDou Navigation Satellite System(BDS)and the E5 band of the Galileo satellite navigation system(Galileo)has been gradually emphasized by academics.On the other hand,unambiguous processing methods for subcarrier modulated signals based on multidimensional tracking loops have flourished,which provides a new way to solve the ambiguity problem.An overview of the most representative subcarrier modulated signal processing techniques,focusing on the achievements made in the last decade,is presented in this article,which can be a starting point for the researchers who start their study in this area.Furthermore,we aim to present a complete review on the recent breakthroughs that have taken place within this research area,providing links to the most interesting and successful advances in this research field.Remaining challenges with prospects are also given.展开更多
基金National Basic Research Program of China(No.2010CB731805)
文摘The Galileo E1 open service （OS） and the global positioning system （GPS） L1C are intending to use the multiplexed binary offset carrier （MBOC） modulation in E1/L1 band, including both pilot and data components. The impact of data and pilot codes cross-correlation on the distortion of the discriminator function （i.e., the S-curve） is investigated, when only the pilot （or data） components of MBOC signals are tracked. It is shown that the modulation schemes and the receiver configuration （e.g., the correlator spacing） strongly affect the S-curve bias. In this paper, two methods are proposed to optimize the data/pilot code pairs of Galileo E1 OS and GPS L1C. The optimization goal is to obtain the minimum average S-curve bias when tracking only the pilot components a the specific correlator spacing. Figures of merit, such as S-curve bias, correlation loss and code tracking variance have been adopted for analyzing and comparing the un-optimized and optimized code pairs. Simulation results show that the optimized data/pilot code pairs could significantly mitigate the intra-channel codes cross-correlation, and then improve the code tracking performance of MBOC signals.
基金supported by National Natural Science Foundation of China,under Grant No.42274018,and National Key Research and Development Program of China under Grant 2021YFA0716600。
文摘Subcarrier modulated signals are widely used in the new generation of Global Navigation Satellite Systems(GNSS)to improve spectral compatibility and ranging accuracy.The unique structure of subcarrier modulated signals poses an ambiguity threat to acquisition and tracking,rendering traditional GNSS signal processing algorithms unsuitable.Designing unambiguous acquisition and tracking as well as observation extraction techniques for subcarrier modulated signals that can realize the high ranging accuracy potential while avoiding the ambiguity threat is a topic of common interest in both academia and industry.Numerous studies have addressed the ambiguity elimination problem of subcarrier modulated signals.However,to the best of our knowledge,no updated reviews on this topic reflecting recent advances in the field have been presented in the past few years.On the one hand,the unique composite subcarrier modulated signal structure in the B1 and B2 bands of the BeiDou Navigation Satellite System(BDS)and the E5 band of the Galileo satellite navigation system(Galileo)has been gradually emphasized by academics.On the other hand,unambiguous processing methods for subcarrier modulated signals based on multidimensional tracking loops have flourished,which provides a new way to solve the ambiguity problem.An overview of the most representative subcarrier modulated signal processing techniques,focusing on the achievements made in the last decade,is presented in this article,which can be a starting point for the researchers who start their study in this area.Furthermore,we aim to present a complete review on the recent breakthroughs that have taken place within this research area,providing links to the most interesting and successful advances in this research field.Remaining challenges with prospects are also given.
