High Dynamic GPS Frequency Tracking Using Block Processing Techniques
Proc. of the ION National Technical Meeting, (2000)Abstract
The application of digital signal processing techniques to blocks
of samples instead of sequential processing, has become a viable
option in GPS with the recent development of software receivers.
These digital signal processing (DSP) techniques are generally referred
to as block-processing techniques. The dynamic behavior of the GPS
signal due to line-of-sight velocity and oscillator effects, is reflected
in a change of the signal's carrier frequency and code-rate. Block
processing techniques have been shown to be invaluable for joint
time-frequency estimation in speech-processing and sonar applications,
and are well suited for the joint time-frequency estimation of the
GPS carrier-frequencies and code-rates under dynamically challenging
conditions. This paper describes a method that utilizes both the
Short-Time Fourier Transform (STFT) and interpolation techniques
to obtain insight in the dynamic behavior of the GPS signal. The
proposed method enables the user to observe changes in frequency
that would not be possible with conventional sequential methods.