Influence of phase truncation noise on GPS DLL tracking performance

A method is presented to reduce the noise in pseudo-range measurements by global positioning system (GPS) receivers. The phase truncation noise was found to be related to the intermediate frequency sampling rate. The intermediate frequency sampling rate was then optimized to reduce the noise. Simulations show that intermediate frequency sampling rates that are higher and nearer than an integer multiple of the pseudo-code rate will minimize the noise. The high resolution, low phase drift optimized intermediate frequency sampling rate improves the tracking accuracy in GPS receivers.