Patent ID: 10514466

Abstract:
Methods and systems for demodulating GNSS navigation data bits in conditions that can cause a Doppler error, such as a GNSS receiver operating under a poor clock condition, in one aspect, include: receiving a modulated Global Navigation Satellite System (GNSS) carrier signal, wherein the GNSS carrier signal includes navigation bits; compensating for a Doppler error of the GNSS carrier signal using Doppler error compensation frequencies, wherein the compensating comprises determining in-phase (I) correlation results and quadrature (Q) correlation results at the Doppler error compensation frequencies; calculating dot products using the I correlation results and the Q correlation results from the compensating; determining a dot product from the calculated dot products having a maximum absolute value; and demodulating the GNSS carrier signal using the determined dot product having the maximum absolute value to extract the navigation bits from the GNSS carrier signal.