Frequency synchronization Using GPS Carrier Phase
We propose a new scheme of frequency synchronization using GPS
carrier phase based on fuzzy and PD controller. Using carrier phase
double-difference with respect to receivers and time, the remote OCXO
clock can be steered to obtain an excellent performance through
weighting least square estimation and appropriate controllers. The
accuracy of the remote clock can be improved from about to about a few parts
in for averaging times of one day over a 30-meter baseline. Moreover,
the zero-baseline tests with the common high-performance cesium clock
show that our system has a frequency stability of a few parts in
for averaging times of one day. Experimental results show that our
system is sound and cost-effective in many applications, such as
the PRS (Primary Reference Source) of telecommunication network,
the frequency traceable to the national standard for frequency
calibration laboratory, instrument calibrations, etc. Combining
the rubidium atomic oscillator, low-cost GPS engines (with carrier
phase option) and other data links for the long baseline applications
is currently under investigation.
