Title :
Frequency calibration of A/D converter in software GPS receivers
Author :
Liou, L.L. ; Lin, D.M. ; Tsui, J.B. ; Schamus, J. ; Morton, J.T.
Author_Institution :
Air Force Res. Lab.
Abstract :
This paper presents a software-based method to calibrate analog-to-digital converter (ADC) sampling frequency in a software GPS receiver. Two front-end systems of a GPS software receiver were used in this study. The sampling frequencies of the ADC were found deviated from the nominal values provided by the manufacturers. Software algorithm was developed to calibrate the sampling frequencies. The algorithm is based on the initial-code-phase velocity and the carrier-phase velocity of the GPS signals at L1 frequency obtained by software receiver measurements. Allan variance analysis of this frequency characterization method is also included in this study
Keywords :
Global Positioning System; analogue-digital conversion; calibration; frequency measurement; radio receivers; signal sampling; software radio; Allan variance analysis; analog-to-digital converter; frequency calibration; frequency characterization; front-end systems; phase velocity; sampling frequency; software GPS receivers; software algorithm; software-based method; Analog-digital conversion; Calibration; Frequency conversion; Frequency measurement; Global Positioning System; Manufacturing; Sampling methods; Software algorithms; Software measurement; Velocity measurement;
Conference_Titel :
Frequency Control Symposium and Exposition, 2005. Proceedings of the 2005 IEEE International
Conference_Location :
Vancouver, BC
Print_ISBN :
0-7803-9053-9
DOI :
10.1109/FREQ.2005.1574012
