Patent ID: 8098765

Claim:
A method of processing a Global Positioning System (GPS) signal, comprising: transforming a time domain GPS signal extending over a plurality of milliseconds to a frequency domain GPS signal, wherein the frequency domain GPS signal has a frequency bin spacing of an inverse of the plurality of milliseconds; and correlating the frequency domain GPS signal with a frequency domain pseudorandom noise (PRN) signal at a plurality of frequencies, said correlating comprising: performing a circular shift on the frequency domain GPS signal by an amount corresponding to one of the plurality of frequencies; downsampling the shifted frequency domain GPS signal to produce a shifted and downsampled frequency domain GPS signal that has the same frequency bin spacing as a frequency bin spacing of the frequency domain PRN signal; multiplying the shifted and downsampled frequency domain GPS signal by the frequency domain PRN signal to produce a frequency domain correlated signal; and transforming the frequency domain correlated signal into a time domain correlated signal extending over a single millisecond.