method and system for dissolution of the akquisitionsmehrdeutigkeit and the problem of false einrastens the composition of boc (n, n) - modulated signalsin particular, for satellitenpositionierungs / navigation systems

摘要

A method and a system for the acquisition and tracking of BOC (n,n) modulated codes are described, in which a correlation function is locally generated at a receiver terminal using a code wa according to the relationship wa(τ) = c(τn)- a⋅prn⁢τn +Tc  ̸2- prn τn- Tc ̸2wherein c(τ) is a local replica of the BOC modulated pseudo-random noise code with delay τn, prn(τ) is a replica of a unmodulated pseudo-random noise code, and a is a predeterminable weight coefficient.Said correlation function is used in an acquisition test function according to the formula xBOC(n)-a⋅xBOC⁢/PRN(n+1)-xBOC/PRN⁢n-12wherein xBOC is the autocorrelation function of the BOC modulated pseudo-random noise code acquired, and xBOC/PRN is the cross correlation function between said acquired BOC modulated pseudo-random noise code and the early and late local replica of the unmodulated pseudo-random noise code, respectively. Said test function is used to recognize a code acquisition, if a value of said test function is higher than a predetermined threshold.