Patent ID: 6603803
Filing Date: 2003-08-05
Classification: G01S,H04B

Abstract:
An apparatus for processing at least one satellite-based navigation broadcast signal that includes a carrier frequency signal modulated by a Pseudo Random Code (PRN) signal, comprising:an intermediate frequency (IF) processor configured to downconvert the broadcast signal to generate a first channel signal; an angle rotator configured to further downconvert the first channel signal, to thereby recover the PRN signal from the broadcast signal; a signal generator configured to generate N gated PRN signals, wherein the N gated PRN signals are generated based on a local replica PRN signal time-divided by M intervals within a chip period of the local replica PRN signal, and N and M are positive integers; a first plurality of correlators each of which is configured to multiply a respective one of N gated PRN signals with a first phase signal of the PRN signal to generate a respective correlation value in a first plurality correlation values; a carrier lock loop coupled to the angle rotator and configured to recover the carrier frequency signal; and a processor configured to adjust timing of the carrier lock loop based on the first plurality of correlation values in order to accurately track the carrier frequency signal.