Patent ID: 6628234
Filing Date: 2003-09-30
Classification: G01S

Abstract:
A method for processing positioning signals in a ranging receiver in a stand-alone mode, comprising:collecting pseudorange samples from positioning signals received at the ranging receiver from a plurality of satellites, the pseudorange samples comprising message data modulation, each satellite having an associated Gold code; selecting a previously determined carrier frequency offset (CFO) from a plurality of directly extracted CFOs; compensating the pseudorange samples for the selected CFO; removing the message data modulation from the pseudorange samples; stacking the pseudorange samples for each satellite; correlating the Gold code associated with each satellite to generate a pseudorange time sequence for the satellite; determining whether an adequate correlation peak exists in each pseudorange time sequence; and determining a pseudorange for the ranging receiver based on the correlation peaks when an adequate correlation peak exists in each pseudorange time sequence.