Patent ID: 7305021
Filing Date: 2007-12-04
Classification: G01S,H04B

Abstract:
1. A method for computing prompt and early-minus-late in-phase and quadrature summed accumulations for a plurality of signals from a plurality of channels comprising the steps of: representing a carrier replica signal from the at least one channel from the plurality of channels as a carrier replica sign and a carrier replica magnitude; representing signal data from the at least one channel of the plurality of channels as at least one signal word; computing a baseband mixed sign as a function of the carrier replica sign and the at least one signal word; computing a baseband mixed magnitude as a function of the carrier replica magnitude; selecting a pseudo-random number (PRN) code having a prompt PRN code and an early-minus-late PRN code; representing the prompt PRN code as a prompt PRN code sign; computing a fully mixed prompt integrand sign as a function of the baseband mixed sign and the prompt PRN code sign; representing the early-minus-late PRN code as an early-minus-late PRN code sign and an early-minus-late PRN code zero mask; computing a fully mixed early-minus-late integrand sign as a function of the baseband mixed sign and the early-minus-late PRN code sign; computing at least one set of prompt integrand value words as a function of the fully mixed prompt integrand sign and the baseband mixed magnitude; computing at least one set of early-minus-late integrand value words as a function of the fully mixed early-minus-late integrand sign, the baseband mixed magnitude, and early-minus-late PRN code zero mask; computing prompt in-phase and quadrature summed accumulations for the plurality of channels for an accumulation interval as functions of the number of significant bits in the at least one set of prompt integrand value words and as functions of the values associated with the at least one set of prompt integrand value words; and computing early-minus-late in-phase and quadrature summed accumulations for the plurality of channels as functions of the number of significant bits in the at least one set of early-minus-late integrand value words and as functions of the values associated with the at least one set of early-minus-late integrand value words; and supplying the prompt and early-minus-late in-phase and quadrature summed accumulations to a software receiver to compute navigation data.