Patent ID: 7391364

Claim:
A correlating circuit of a Global Positioning System (GPS) receiver, comprising: a data receiving register, adapted to store a sampled digital data as an IF data; an interface controller coupled to the data receiving register and an external memory, for sequentially transmitting data sent from an RF front end from the external memory to the data receiving register; and a correlator coupled to the data receiving register, adapted to receive the IF data and identify a transmission satellite transmitting the IF data among a plurality of satellites, according to a operation of the IF data, each of C/A codes of the satellites, and each of corrected frequency codes for correcting Doppler effect, comprising: a C/A code generating unit, sequentially and in parallel generating and outputting a portion of bits of each of the C/A codes representing each of the satellites; a Doppler generating unit, sequentially and in parallel generating and outputting a portion of bits of each of the corrected frequency codes for correcting Doppler effect; a multiplication unit coupled to the C/A code generating unit and the Doppler generating unit, sequentially multiplying the portion of bits of each of the C/A codes from the C/A code generating unit, the portion of bits of each of the corrected frequency codes from the parallel Doppler generating unit, and the IF data; and a digital summation and peak detector coupled to the multiplication unit, adding products therefrom for generating a plurality of summation values and searching a maximum among the summation values thereof for identifying the satellite transmitting the IF data.