TY - GEN
T1 - Design and implementation of a multi-signal-structure GNSS signal simulator using low IF digital quadrature modulation
AU - Kou, Yanhong
AU - Zhang, Bo
AU - Zhao, Yun
PY - 2008
Y1 - 2008
N2 - Signal simulators play an important role in research and design validation of Global Navigation Satellite System (GNSS), especially of user equipments. They simulate GNSS signals in various conditions in order to provide signal sources for debug and test of receivers and their key components. They can also serve to test and assess the performance of new signal structure before the corresponding new satellites are deployed. This paper presents a Software Defined Radio (SDR) architecture using a low-IF digital quadrature modulation method to accommodate multi-signal-structure, multi-channel and multi-level-output on a common hardware platform. The simulator can work at four kinds of output mode: (1) the navigation data and measurement data; (2) the digital IF signals; (3) the analog IF signals; (4) the analog RF signals of all visible satellites after combining several user-specified carrier frequencies. The signal model, system implementation, frequency plan and power control plan are addressed in detail. Realtime digital IF signal synthesis is performed in a high-capacity FPGA. The first-stage quadrature modulation is carried out at a low-IF to ensure the signal quality and easy processing with limited clock rate. Then the combined plural signals for all visible satellite for each carrier frequency are digitally up-converted before being sent to the DAC, where the output IF can be configured by the interpolating factor and the second LO frequency. The RF LO signals are generated by a PLL frequency synthesizer with a programmable frequency dividing ratio. The prototype of the simulator is developed and tested with a commercial GPS receiver and a self-developed software receiver. All the four-level outputs of the simulator can use RINEX files as ephemeris sources to enable true position solution. The accuracy and quality of simulated signals are verified in the spectrum, correlation, measurement, and position domains.
AB - Signal simulators play an important role in research and design validation of Global Navigation Satellite System (GNSS), especially of user equipments. They simulate GNSS signals in various conditions in order to provide signal sources for debug and test of receivers and their key components. They can also serve to test and assess the performance of new signal structure before the corresponding new satellites are deployed. This paper presents a Software Defined Radio (SDR) architecture using a low-IF digital quadrature modulation method to accommodate multi-signal-structure, multi-channel and multi-level-output on a common hardware platform. The simulator can work at four kinds of output mode: (1) the navigation data and measurement data; (2) the digital IF signals; (3) the analog IF signals; (4) the analog RF signals of all visible satellites after combining several user-specified carrier frequencies. The signal model, system implementation, frequency plan and power control plan are addressed in detail. Realtime digital IF signal synthesis is performed in a high-capacity FPGA. The first-stage quadrature modulation is carried out at a low-IF to ensure the signal quality and easy processing with limited clock rate. Then the combined plural signals for all visible satellite for each carrier frequency are digitally up-converted before being sent to the DAC, where the output IF can be configured by the interpolating factor and the second LO frequency. The RF LO signals are generated by a PLL frequency synthesizer with a programmable frequency dividing ratio. The prototype of the simulator is developed and tested with a commercial GPS receiver and a self-developed software receiver. All the four-level outputs of the simulator can use RINEX files as ephemeris sources to enable true position solution. The accuracy and quality of simulated signals are verified in the spectrum, correlation, measurement, and position domains.
UR - https://www.scopus.com/pages/publications/69949140703
M3 - 会议稿件
AN - SCOPUS:69949140703
SN - 9781605606897
T3 - 21st International Technical Meeting of the Satellite Division of the Institute of Navigation, ION GNSS 2008
SP - 714
EP - 728
BT - 21st International Technical Meeting of the Satellite Division of the Institute of Navigation, ION GNSS 2008
T2 - 21st International Technical Meeting of the Satellite Division of the Institute of Navigation, ION GNSS 2008
Y2 - 16 September 2008 through 19 September 2008
ER -