Method and apparatus for correlating signals received from a navigation satellite system

A method, comprising:

• storing a plurality of samples of a signal in a buffer implemented in a memory device, the signal corresponding to a navigation system;
• determining, with one or more integrated circuit devices, a plurality of starting locations in the buffer, the plurality of starting locations corresponding to a plurality of correlations to be calculated, wherein ones of at least some of the starting locations are determined based on respective code phases with which the corresponding correlations are to be performed;
• calculating, with one or more integrated circuit devices, a plurality of correlations using i) a plurality of local replica signals, and ii) data read from the buffer using the plurality of starting locations, wherein the local replica signals correspond to pseudo random number (PRN) codes utilized by transmitting devices in the navigation system;
• and
• using, with one or more integrated circuit devices, the plurality of correlations to one or more of i) detect PRN codes in the signal, ii) detect one or more phase shifts associated with PRN codes, or iii) detect one or more frequency shifts associated with PRN codes.