Title :
Influence of oscillator variations on the observed frequency behavior in software-based navigation receivers
Author :
De Haag, Maarten Uijt ; Kelly, Joseph M.
Author_Institution :
Sch. of Electr. Eng. & Comput. Sci., Ohio Univ., Athens, OH, USA
fDate :
3/1/2004 12:00:00 AM
Abstract :
This letter discusses the effects of oscillator behavior such as phase and frequency offsets on the observed frequency behavior in software-based receivers. Frequency errors introduced by the front-end oscillators and sample clocks cause the observed frequency to differ from the actual frequency. Frequency errors directly affect the user velocity and position estimates in navigation receivers unless these errors are explicitly estimated and removed. This letter will show the derivation of a quantitative relationship between the observed frequency and the true frequency of the received signal in the presence of local oscillator and sample rate errors.
Keywords :
Doppler effect; Global Positioning System; radio receivers; radiofrequency oscillators; signal sampling; software radio; band pass sampling; carrier-phase estimation; code estimation; frequency errors; front-end oscillators; local oscillator; observed frequency behavior; oscillator variations; sample rate errors; software-based navigation receivers; software-based radios; user position estimates; user velocity estimates; Clocks; Frequency estimation; Frequency locked loops; Global Positioning System; Local oscillators; Radio navigation; Sampling methods; Satellites; Signal processing; Working environment noise;
Journal_Title :
Signal Processing Letters, IEEE
DOI :
10.1109/LSP.2003.822595
