Abstract:
An integrated global navigation satellite system (GNSS) receiver may be operable to decompose GNSS IF signals associated with GPS satellites and/or GLONASS satellites into a constituent narrowband GPS data stream and/or a plurality of constituent narrowband GLONASS data streams utilizing, for example, a GPS IF tuner and/or one or more GLONASS IF tuners. The narrowband GLONASS data streams and/or the narrowband GPS data stream may be processed at reduced sampling rates utilizing a shared sample memory in the integrated GNSS receiver. The narrowband GLONASS data streams and/or the narrowband GPS data stream may be stored in allocated sections of the shared sample memory. The stored narrowband GLONASS data streams and/or the stored narrowband GPS data stream may be processed using a correlation such as a fast Fourier transform (FFT) correlation.
Abstract:
A method of tracking a code phase includes configuring local correlators with a first de-spreading local function; de-spreading an incoming signal with the first de-spreading local function to generate a first correlation output; determining a range estimate based on the first de-spreading local function; reconfiguring the local correlators with a second de-spreading local function when a delay-locked loop has locked to a correct correlation peak of the first correlation output; de-spreading the incoming signal with the second de-spreading local function to generate a second correlation output; determining a range estimate based on the second de-spreading local function that has a higher resolution than the range estimate based on the first de-spreading local function; and determining if the delay-locked loop has lost a lock to the correct correlation peak of the second correlation output to determine that the local correlators need to be reconfigured with the first de-spreading local function.