Abstract: The carrier phase ready coherent acquisition of a global navigation satellite system (GNSS) snapshot signal includes receiving in a snapshot receiver different GNSS signals from correspondingly different GNSS satellites, and performing multi-hypothesis (MH) acquisition upon each of GNSS signal in order to produce a complete set of secondary code index hypotheses, each hypothesis producing a corresponding acquisition result according to an identified peak at a correct code-phase and Doppler frequency. The secondary code index hypotheses are adjusted for each different GNSS signal based upon a flight time difference determined for each GNSS satellite, so as to produce a new set of hypotheses. Finally, one of the hypotheses in the new set may be selected as a correct hypothesis according to a predominate common index amongst the hypotheses in the new set, and the acquisition results for each of the different GNSS signals may be filtered utilizing the correct hypothesis.
Abstract: Embodiments of the present invention provide a method, system and computer program product for bit transition enhanced direct position estimation (DPE) from global navigation satellite system (GNSS) signals and includes the reception in a GNSS receiver of signals from multiple, different satellites in multiple satellite constellations adapted for use with the GNSS. The method estimates the GNSS receiver parameters position, velocity, clock bias, clock drift, and optionally and if unknown, the receiver time. The method generates a model of the received GNSS signals that depends on the receiver parameters. Uniquely, the method includes the synchronization of both a primary code and also a secondary code in the received GNSS signal model, in addition to time delays, Doppler shifts, and other relevant parameters for positioning. Finally, if the secondary code of a particular signal is unknown, the method determines the combination of bit transitions that maximizes the optimization problem.