Patent ID: 8160124

Claim:
A code tracking loop circuit configured to detect timing differences between a pseudo-random noise (PRN) modulated navigation satellite system (NSS) signal and a reference PRN signal, the circuit comprising: a correlator block configured to generate four input terms, wherein each input term is a correlation between a phase shifted reference PRN signal and the NSS signal, wherein the four input terms consist of an early (E) input term, a prompt (P) input term, a late (L) input term, and one of a very early (VE) input term and a very late (VL) input term; and a discriminator for using the four input terms to determine phase differences between the PRN modulated NSS signal and the reference PRN signal, the discriminator being implemented with a differential Teager-Kaiser operator, wherein a discriminator output corresponds to at least a portion of a timing difference between the reference PRN signal and the PRN modulated NSS signal.