A novel GPS signal acquisition algorithm using differential C/A codes and block processing techni... more A novel GPS signal acquisition algorithm using differential C/A codes and block processing techniques was proposed.It was integrated with the advantages of serial correlation method in the time domain,differential digital matched filter method and block processing techniques in the frequency domain,and realized a good compromise be-tween acquisition time and resources consumption,which not only improved the acquisition speed but also reduced the hardware consumption while maintaining an identical processing gain.The experiment results show the algorithm can work well.
The high-order binary offset carrier (BOC) modulation can make full use of the allocated frequenc... more The high-order binary offset carrier (BOC) modulation can make full use of the allocated frequency spectrum resource to improve the compatibility with other GNSS signals in the same band, the anti-multipath capability and the code tracking accuracy. High-order BOC signals have been adopted by Galileo and COMPASS system. The distortions of high-order BOC signals and their impacts on signal performance need to be further explored. Based on the 2nd-order threat model of Evil Waveform (2OS EWF) proposed by ICAO, three types of threat mode—TMA, TMB, and TMC for BOC signals are modeled in this paper. The impacts of various models and parameters on the correlation function are analyzed. Next, the code tracking biases are calculated under different combinations of threat modes, distortion parameters, and correlator spacing. Finally, the optimum selections of correlator spacing for receivers are proposed based on simulation results.
Proceedings of the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2012), Sep 21, 2012
ABSTRACT One of the most important performance parameters of a GNSS RF (radio frequency) constell... more ABSTRACT One of the most important performance parameters of a GNSS RF (radio frequency) constellation simulator is the pseudorange accuracy. Assuming that mathematical model of the simulator can calculate the pseudorange correctly, the SV (satellite vehicle) code phase error in the generated RF signal still exists due to digitization-induced error and analog distortion in the non-ideal signal generation chain of the RF signal simulator and inaccurately represented navigation message. So far no standard definitions and test methods can be found on simulator specifications. This paper explores a closedloop test method based on a high performance software GNSS receiver. The methodology description is focused on receiver measurement error analysis in strong signal condition with prior knowledge aiding and specialized test receiver design. A single-SV timing and ranging algorithm is presented to solve the time alignment and pseudorange ambiguity problems. The methods are validated through extensive closed-loop test at both digital IF (intermediate frequency) signal level and RF signal level using GNSS RF constellation simulators from four manufacturers.
International Telemetering Conference Proceedings, Oct 1, 2005
High dynamic and multi-channel digital GPS receiver can handle the signals with high dynamic rang... more High dynamic and multi-channel digital GPS receiver can handle the signals with high dynamic range, low S/N ratio and refresh data quickly. A hardware design of high dynamic GPS digital receiver is given. Based on analysis of the effect that high dynamic movement makes on the receiving signals, a scheme of fast-acquisition high dynamic GPS receiver is presented. Exact reckoning of the orbit parameters and the satellite clock parameters are integrated with appropriate algorithms. A DDLL is used to precisely estimate the C/A code delay, a CPAFC loop and a Costas loop to precisely estimate the carrier frequency and phase. The DDLL is assisted with carrier phase. The experimental results show that the receiver meets the design request.
ABSTRACT We consider the estimation of Doppler shift of the data-modulated signal in the direct s... more ABSTRACT We consider the estimation of Doppler shift of the data-modulated signal in the direct sequence spread spectrum (DS/SS) communication system. A new open-loop Doppler shift estimation algorithm is developed by taking advantage of the priori knowledge that correlation peak is Sinc-function of Doppler shift in the DS/SS receiver. The proposed algorithm samples correlation peaks on different Doppler shifts and fits these samples to the correlation peak curve using a nonlinear least squares method. Performance of the proposed method is demonstrated by statistical analysis and numerical simulation. And a comparison with the four-quadrant frequency discriminator algorithm (FQFD) is given.
International Telemetering Conference Proceedings, Oct 1, 2005
With the development of Internet and the urgent need for GIS (Geographic Information System), XML... more With the development of Internet and the urgent need for GIS (Geographic Information System), XML (eXtensible Markup Language) provides a powerful new way for new web application. This paper makes a research on the application of SVG based on XML in the WebGIS (World Wide Web Geographical Infromation System). In this paper, the characteristics of XML are illuminated in short; the application of XML in WebGIS is discussed and the features of SVG and its usage with XML are presented; a design of SVG based on XML in the WebGIS system is given.
International Telemetering Conference Proceedings, Oct 1, 2004
To enhance the production management of the rod-pumped wells in the oil field, using a high perfo... more To enhance the production management of the rod-pumped wells in the oil field, using a high performance single-chip as the processor, a field monitor system based on GPRS is researched and developed. In the paper the hardware design and software design are expatiated, the sampling frequency and determination rules for the running state are analyzed, the rational communication protocol is designed to ensure the reliable message transmission and reduce the communication fees. In the end the field monitor system is successfully implemented and verified in practice, part of data transmission result is illustrated.
Geomatics and Information Science of Wuhan University, 2009
This paper focuses on close-loop test of code tracking noise and multipath error en-velope of MBO... more This paper focuses on close-loop test of code tracking noise and multipath error en-velope of MBOC signals based on a digital IF signal simulator and a software receiver. The experimental results were analyzed and compared with theoretical expectations,and the accuracy improvements of MBOC(6,1,1/11) versus BOC(1,1) and BPSK-R(1) are validated effectively.
A novel GPS signal acquisition algorithm using differential C/A codes and block processing techni... more A novel GPS signal acquisition algorithm using differential C/A codes and block processing techniques was proposed.It was integrated with the advantages of serial correlation method in the time domain,differential digital matched filter method and block processing techniques in the frequency domain,and realized a good compromise be-tween acquisition time and resources consumption,which not only improved the acquisition speed but also reduced the hardware consumption while maintaining an identical processing gain.The experiment results show the algorithm can work well.
The high-order binary offset carrier (BOC) modulation can make full use of the allocated frequenc... more The high-order binary offset carrier (BOC) modulation can make full use of the allocated frequency spectrum resource to improve the compatibility with other GNSS signals in the same band, the anti-multipath capability and the code tracking accuracy. High-order BOC signals have been adopted by Galileo and COMPASS system. The distortions of high-order BOC signals and their impacts on signal performance need to be further explored. Based on the 2nd-order threat model of Evil Waveform (2OS EWF) proposed by ICAO, three types of threat mode—TMA, TMB, and TMC for BOC signals are modeled in this paper. The impacts of various models and parameters on the correlation function are analyzed. Next, the code tracking biases are calculated under different combinations of threat modes, distortion parameters, and correlator spacing. Finally, the optimum selections of correlator spacing for receivers are proposed based on simulation results.
Proceedings of the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2012), Sep 21, 2012
ABSTRACT One of the most important performance parameters of a GNSS RF (radio frequency) constell... more ABSTRACT One of the most important performance parameters of a GNSS RF (radio frequency) constellation simulator is the pseudorange accuracy. Assuming that mathematical model of the simulator can calculate the pseudorange correctly, the SV (satellite vehicle) code phase error in the generated RF signal still exists due to digitization-induced error and analog distortion in the non-ideal signal generation chain of the RF signal simulator and inaccurately represented navigation message. So far no standard definitions and test methods can be found on simulator specifications. This paper explores a closedloop test method based on a high performance software GNSS receiver. The methodology description is focused on receiver measurement error analysis in strong signal condition with prior knowledge aiding and specialized test receiver design. A single-SV timing and ranging algorithm is presented to solve the time alignment and pseudorange ambiguity problems. The methods are validated through extensive closed-loop test at both digital IF (intermediate frequency) signal level and RF signal level using GNSS RF constellation simulators from four manufacturers.
International Telemetering Conference Proceedings, Oct 1, 2005
High dynamic and multi-channel digital GPS receiver can handle the signals with high dynamic rang... more High dynamic and multi-channel digital GPS receiver can handle the signals with high dynamic range, low S/N ratio and refresh data quickly. A hardware design of high dynamic GPS digital receiver is given. Based on analysis of the effect that high dynamic movement makes on the receiving signals, a scheme of fast-acquisition high dynamic GPS receiver is presented. Exact reckoning of the orbit parameters and the satellite clock parameters are integrated with appropriate algorithms. A DDLL is used to precisely estimate the C/A code delay, a CPAFC loop and a Costas loop to precisely estimate the carrier frequency and phase. The DDLL is assisted with carrier phase. The experimental results show that the receiver meets the design request.
ABSTRACT We consider the estimation of Doppler shift of the data-modulated signal in the direct s... more ABSTRACT We consider the estimation of Doppler shift of the data-modulated signal in the direct sequence spread spectrum (DS/SS) communication system. A new open-loop Doppler shift estimation algorithm is developed by taking advantage of the priori knowledge that correlation peak is Sinc-function of Doppler shift in the DS/SS receiver. The proposed algorithm samples correlation peaks on different Doppler shifts and fits these samples to the correlation peak curve using a nonlinear least squares method. Performance of the proposed method is demonstrated by statistical analysis and numerical simulation. And a comparison with the four-quadrant frequency discriminator algorithm (FQFD) is given.
International Telemetering Conference Proceedings, Oct 1, 2005
With the development of Internet and the urgent need for GIS (Geographic Information System), XML... more With the development of Internet and the urgent need for GIS (Geographic Information System), XML (eXtensible Markup Language) provides a powerful new way for new web application. This paper makes a research on the application of SVG based on XML in the WebGIS (World Wide Web Geographical Infromation System). In this paper, the characteristics of XML are illuminated in short; the application of XML in WebGIS is discussed and the features of SVG and its usage with XML are presented; a design of SVG based on XML in the WebGIS system is given.
International Telemetering Conference Proceedings, Oct 1, 2004
To enhance the production management of the rod-pumped wells in the oil field, using a high perfo... more To enhance the production management of the rod-pumped wells in the oil field, using a high performance single-chip as the processor, a field monitor system based on GPRS is researched and developed. In the paper the hardware design and software design are expatiated, the sampling frequency and determination rules for the running state are analyzed, the rational communication protocol is designed to ensure the reliable message transmission and reduce the communication fees. In the end the field monitor system is successfully implemented and verified in practice, part of data transmission result is illustrated.
Geomatics and Information Science of Wuhan University, 2009
This paper focuses on close-loop test of code tracking noise and multipath error en-velope of MBO... more This paper focuses on close-loop test of code tracking noise and multipath error en-velope of MBOC signals based on a digital IF signal simulator and a software receiver. The experimental results were analyzed and compared with theoretical expectations,and the accuracy improvements of MBOC(6,1,1/11) versus BOC(1,1) and BPSK-R(1) are validated effectively.
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Papers by Yanhong Kou