Mitigating multipath errors in a GPS receiver

摘要

A global positioning satellite (GPS) receiver that includes a radio frequency (RF) receiver receiving a first GPS signal (e.g. line of sight) from a GPS satellite and a processor. The processor is configured to correlate the first GPS signal with a plurality of reference signals to produce a plurality of correlations, detect a transition between receiving the first GPS signal and receiving a second GPS signal (e.g. multipath) from the GPS satellite based on a â phase shiftâ in the correlations (i.e. a shift in the code phase related to a change in the time delay applied to the reference signals), and if the transition is detected, compensate for the â phase shiftâ when computing a range to the GPS satellite. The receiver may receive a respective GPS signal from each of a plurality of GPS satellites. The processor may interpolate the correlations to determine a phase shift for balancing an early correlation value and a late correlation value after the transition occurs. The processor may also compare the phase shift to a threshold and detect the transition when the phase shift is greater than the threshold.