Multipath compensation for code phase signals

Claim 1

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite code phase SATPS signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧2) for the first correlation function A I (t) for which the code phase shift differences p I -e I ,i =Δ I ,e,i have selected values; (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the code phase shift differences p M -e M ,i =Δ M ,e,i have selected values; (7) forming a sequence of U correlation amplitude ratios defined by the relations x e ,i =(A M (e M ,i)/A M (p M ))-(A I (e I ,i)/A I (p I )) for i=1, . . . , U; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =F.sub.e (x.sub.e,1, x.sub.e,2, . . . , x.sub.e,U), where F e is a selected function of U variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 2

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite code phase SATPS signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧2) for the first correlation function A I (t) for which the code phase shift differences p I -e I ,i =Δ I ,e,i have selected values; (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the code phase shift differences p M -e M ,i =Δ M ,e,i have selected values; (7) forming a sequence of U correlation amplitude ratios defined by the relations x e ,i =(A M (e M ,i)/A M (p M ))-(A I (e I ,i)/A I (p I )) for i=1, . . . , U; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =F.sub.e (x.sub.e,1, x.sub.e,2, . . . , x.sub.e,U), where F e is a selected function of U variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 4

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; V≧2) for the first correlation function A I (t) for which the code phase shift differences p I -l I ,j =Δ I ,l,j have selected values; (6) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift differences p M -l M ,j =Δ M ,l,j have selected values; (7) forming a sequence of V correlation amplitude ratios defined by the relations x l ,i =(A M (l M ,j)/A M (p M ))-(A I (l I ,j)/A I (p I )) for j=1, . . . , V; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =F.sub.l (x.sub.l,1,x.sub.l,2, . . . , x.sub.l,V), where F l is a selected function of V variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 5

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; V≧2) for the first correlation function A I (t) for which the code phase shift differences p I -l I ,j =Δ I ,l,j have selected values; (6) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift differences p M -l M ,j =Δ M ,l,j have selected values; (7) forming a sequence of V correlation amplitude ratios defined by the relations x l ,i =(A M (l M ,j)/A M (p M ))-(A I (l I ,j)/A I (p I )) for j=1, . . . , V; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =F.sub.l (x.sub.l,1,x.sub.l,2, . . . , x.sub.l,V), where F l is a selected function of V variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 7

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift differences p I -e I ,i =Δ I ,e,i have selected values; (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the code phase shift differences p M -e M ,i =Δ M ,e,i have selected values; (7) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; U+V≧2) for the first correlation function A I (t) for which the code phase shift differences p I -l I ,j =Δ I ,l,j have selected values; (8) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift differences p M -l M ,j =Δ M ,l,j have selected values; (9) forming a sequence of L correlation amplitude ratios defined by the relations x e ,i =(A M (e M ,i)/A M (p M )) -(A I (e I ,i)/A I (p I )) for i=1, . . . , U; (10) forming a sequence Of V correlation amplitude ratios defined by the relations x l ,j =(A M (l M ,j)/A M (p M )) -(A I (l I ,j)/A I (p I )) for j=1, . . . , V; (11 ) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =F(x.sub.e,1, . . . , x.sub.e,U, x.sub.l,1, . . . , x.sub.l,V), where F is a selected function of U+V variables; and (12) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 8

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift differences p I -e I ,i =Δ I ,e,i have selected values; (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the code phase shift differences p M -e M ,i =Δ M ,e,i have selected values; (7) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; U+V≧2) for the first correlation function A I (t) for which the code phase shift differences p I -l I ,j =Δ I ,l,j have selected values; (8) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift differences p M -l M ,j =Δ M ,l,j have selected values; (9) forming a sequence of L correlation amplitude ratios defined by the relations x e ,i =(A M (e M ,i)/A M (p M )) -(A I (e I ,i)/A I (p I )) for i=1, . . . , U; (10) forming a sequence Of V correlation amplitude ratios defined by the relations x l ,j =(A M (l M ,j)/A M (p M )) -(A I (l I ,j)/A I (p I )) for j=1, . . . , V; (11 ) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =F(x.sub.e,1, . . . , x.sub.e,U, x.sub.l,1, . . . , x.sub.l,V), where F is a selected function of U+V variables; and (12) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 10

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧2) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (e I ,i)/A I (p I )=r I ,e,i have selected values; (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (e M ,i)/A M (p M )=r M ,e,i have selected values; (7) forming a sequence of U code phase shift differences defined by the relations Y e ,i =(p M -e M ,i)-(p I -e I ,i) for i=1, . . . , U; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =G.sub.e (y.sub.e,1, y.sub.e,2, . . . , y.sub.e,U), where G e is a selected function of U variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 11

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧2) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (e I ,i)/A I (p I )=r I ,e,i have selected values; (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (e M ,i)/A M (p M )=r M ,e,i have selected values; (7) forming a sequence of U code phase shift differences defined by the relations Y e ,i =(p M -e M ,i)-(p I -e I ,i) for i=1, . . . , U; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =G.sub.e (y.sub.e,1, y.sub.e,2, . . . , y.sub.e,U), where G e is a selected function of U variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 13

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; V≧2) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (l I ,j)/A I (p I )=r I ,e,j have selected values; (6) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (l M ,j)/A M (p M )=r M ,l,j have selected values; (7) forming a sequence of V code phase shift differences defined by the relations y l ,j =(p M -l M ,j)-(p I -l I ,j) for j=1, . . . , V; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =G.sub.l (y.sub.l,1, y.sub.l,2, . . . , y.sub.l,V), where G l is a selected function of V variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 14

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; V≧2) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (l I ,j)/A I (p I )=r I ,e,j have selected values; (6) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (l M ,j)/A M (p M )=r M ,l,j have selected values; (7) forming a sequence of V code phase shift differences defined by the relations y l ,j =(p M -l M ,j)-(p I -l I ,j) for j=1, . . . , V; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =G.sub.l (y.sub.l,1, y.sub.l,2, . . . , y.sub.l,V), where G l is a selected function of V variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 16

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (e I ,i)/A I (p I )=r I ,e,i have selected values; (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (e M ,i)/A M (p M )=r M ,e,i have selected values; (7) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; U+V≧2) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (l I ,j)/A I (p I )=r I ,e,j have selected values; (8) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (l M ,j)/A M (p M )=r M ,l,j have selected values; (9) forming a sequence of U code phase shift differences defined by the relations y e ,i =(p M -e M ,i)-(p I -e I ,i) for i=1, . . . , U; (10) forming a sequence Of V code phase shift differences defined by the relations y l ,j =(p M -l M ,j)-(p I -l I ,j) for j=1, . . . , V; (11) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =G(y.sub.e,1, . . . , y.sub.e,U, y.sub.l,1, . . . , y.sub.l,V), where G is a selected function of U+V variables; and (12) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 17

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (e I ,i)/A I (p I )=r I ,e,i have selected values; (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (e M ,i)/A M (p M )=r M ,e,i have selected values; (7) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; U+V≧2) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (l I ,j)/A I (p I )=r I ,e,j have selected values; (8) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (l M ,j)/A M (p M )=r M ,l,j have selected values; (9) forming a sequence of U code phase shift differences defined by the relations y e ,i =(p M -e M ,i)-(p I -e I ,i) for i=1, . . . , U; (10) forming a sequence Of V code phase shift differences defined by the relations y l ,j =(p M -l M ,j)-(p I -l I ,j) for j=1, . . . , V; (11) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =G(y.sub.e,1, . . . , y.sub.e,U, y.sub.l,1, . . . , y.sub.l,V), where G is a selected function of U+V variables; and (12) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 19

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,j <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift differences p I -e I ,i =Δ I ,e,i have selected values, and forming a first sequence of gradient values B I ,e,i =(A I (p I )-A I (e I ,i))/(p I -e I ,i); (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t), for which the code phase shift differences p M -e M ,i =Δ M ,e,i have selected values, and forming a second sequence of gradient values B M ,e,i =(A M (p M )-A M (e M ,i))/(p M -e M ,i); (7) forming a sequence of U gradient differences z e ,i =B M ,e,i -B I ,e,i for i=1, . . . , U; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =H.sub.e (z.sub.e,1, . . . , z.sub.e,U), where H e is a selected function of U variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 20

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,j <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift differences p I -e I ,i =Δ I ,e,i have selected values, and forming a first sequence of gradient values B I ,e,i =(A I (p I )-A I (e I ,i))/(p I -e I ,i); (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t), for which the code phase shift differences p M -e M ,i =Δ M ,e,i have selected values, and forming a second sequence of gradient values B M ,e,i =(A M (p M )-A M (e M ,i))/(p M -e M ,i); (7) forming a sequence of U gradient differences z e ,i =B M ,e,i -B I ,e,i for i=1, . . . , U; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =H.sub.e (z.sub.e,1, . . . , z.sub.e,U), where H e is a selected function of U variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 22

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; V≧1) for the first correlation function A I (t) for which the code phase shift differences p I -l I ,j =Δ I ,l,j have selected values, and forming a first sequence of gradient values B I ,l,j =(A I (p I )-A I (l I ,j))/(p I -l I ,j); (6) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t), for which the code phase shift differences p M -l M ,j =Δ M ,l,j have selected values, and forming a second sequence of gradient values B M ,l,j =(A M (p M )-A M (l M ,j))/(p M -l M ,j); (7) forming a sequence of V gradient differences z l ,j =B M ,l,j -B I ,l,j for j=1, . . . , V; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =H.sub.l (z.sub.l,1, . . . , z.sub.l,V), where H l is a selected function of V variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 23

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; V≧1) for the first correlation function A I (t) for which the code phase shift differences p I -l I ,j =Δ I ,l,j have selected values, and forming a first sequence of gradient values B I ,l,j =(A I (p I )-A I (l I ,j))/(p I -l I ,j); (6) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t), for which the code phase shift differences p M -l M ,j =Δ M ,l,j have selected values, and forming a second sequence of gradient values B M ,l,j =(A M (p M )-A M (l M ,j))/(p M -l M ,j); (7) forming a sequence of V gradient differences z l ,j =B M ,l,j -B I ,l,j for j=1, . . . , V; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =H.sub.l (z.sub.l,1, . . . , z.sub.l,V), where H l is a selected function of V variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 25

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift differences p I -e I ,i =Δ I ,e,i have selected values, and forming a first sequence of gradient values B I ,e,i =(A I (p I )-A I (e I ,i))/(p I -e I ,i); (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the code phase shift differences p M -e M ,i =Δ M ,e,i have selected values, and forming a second sequence of gradient values B M ,e,i =(A M (p M )-A M (e M ,i))/(p M -e M ,i); (7) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; U+V≧2) for the first correlation function A I (t) for which the code phase shift p I -e I ,j =Δ I ,e,j have selected values and forming a first sequence of gradient values B I ,l,j =(A I (p I )-A I (l I ,j))/(p I -l I ,j); (8) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift differences p M -l M ,j =Δ M ,l,j have selected values, and forming a second sequence of gradient values B M ,l,j =(A M (p M )-A M (l M ,j))/(p M -l M ,j); (9) forming a sequence of U gradient differences z e ,i =B M ,e,i -B I ,e,i for i=1, . . . , U; (10) forming a sequence of V gradient differences z e ,j =B M ,e,j -B I ,e,j for j=1, . . . , V; (11) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =H(z.sub.e,1, . . . , z.sub.e,U, z.sub.l,1, . . . , z.sub.l,V), where H is a selected function of U+V variables; and (12) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 26

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift differences p I -e I ,i =Δ I ,e,i have selected values, and forming a first sequence of gradient values B I ,e,i =(A I (p I )-A I (e I ,i))/(p I -e I ,i); (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the code phase shift differences p M -e M ,i =Δ M ,e,i have selected values, and forming a second sequence of gradient values B M ,e,i =(A M (p M )-A M (e M ,i))/(p M -e M ,i); (7) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; U+V≧2) for the first correlation function A I (t) for which the code phase shift p I -e I ,j =Δ I ,e,j have selected values and forming a first sequence of gradient values B I ,l,j =(A I (p I )-A I (l I ,j))/(p I -l I ,j); (8) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift differences p M -l M ,j =Δ M ,l,j have selected values, and forming a second sequence of gradient values B M ,l,j =(A M (p M )-A M (l M ,j))/(p M -l M ,j); (9) forming a sequence of U gradient differences z e ,i =B M ,e,i -B I ,e,i for i=1, . . . , U; (10) forming a sequence of V gradient differences z e ,j =B M ,e,j -B I ,e,j for j=1, . . . , V; (11) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =H(z.sub.e,1, . . . , z.sub.e,U, z.sub.l,1, . . . , z.sub.l,V), where H is a selected function of U+V variables; and (12) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 28

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the correlation amplitude ratios r I ,e,i =A I (e I ,i)/A I (p I ) have selected values, and forming a first sequence of gradient values B I ,e,i =(A I (p I )-A I (e I ,i))/(p I -e I ,i); (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t), for which the correlation amplitude ratios r M ,e,i =A M (e M ,i)/A M (p M ) have selected values, and forming a second sequence of gradient values B M ,e,i =(A M (p M ) -A M (e M ,i))/(p M -e M ,i); (7) forming a sequence of U gradient differences z e ,i =B M ,e,i -B I ,e,i for i=1, . . . , U; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =K.sub.e (z.sub.e,1, . . . , z.sub.e,U), where K e is a selected function of U variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 29

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the correlation amplitude ratios r I ,e,i =A I (e I ,i)/A I (p I ) have selected values, and forming a first sequence of gradient values B I ,e,i =(A I (p I )-A I (e I ,i))/(p I -e I ,i); (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t), for which the correlation amplitude ratios r M ,e,i =A M (e M ,i)/A M (p M ) have selected values, and forming a second sequence of gradient values B M ,e,i =(A M (p M ) -A M (e M ,i))/(p M -e M ,i); (7) forming a sequence of U gradient differences z e ,i =B M ,e,i -B I ,e,i for i=1, . . . , U; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =K.sub.e (z.sub.e,1, . . . , z.sub.e,U), where K e is a selected function of U variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 31

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=P I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of V late code phase shift values l i ,j >p I (j =1, . . . , V; V≧1) for the first correlation function A I (t.sub.), for which the correlation amplitude ratios r I ,l,j =A I (l I ,j)/A I (p I ) have selected values, and forming a sequence of gradient values B I ,l,j =(A I (p I )-A I (l I ,j))/(p I -l I ,j); (6) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t), for which the correlation amplitude ratios r M ,l,j =A M (l M ,l)/A M (p M ) have selected values, and forming a sequence of gradient values B M ,l,j =(A M (p M )-A M (l M ,j))/(p M -l M ,j); (7) forming a sequence of V gradient differences z l ,j =B M ,l,j -B I ,l,j for j=1, . . . ,V; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =K.sub.l (z.sub.l,1, . . . , z.sub.l,V), where K l is a selected function of V variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 32

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=P I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of V late code phase shift values l i ,j >p I (j =1, . . . , V; V≧1) for the first correlation function A I (t.sub.), for which the correlation amplitude ratios r I ,l,j =A I (l I ,j)/A I (p I ) have selected values, and forming a sequence of gradient values B I ,l,j =(A I (p I )-A I (l I ,j))/(p I -l I ,j); (6) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t), for which the correlation amplitude ratios r M ,l,j =A M (l M ,l)/A M (p M ) have selected values, and forming a sequence of gradient values B M ,l,j =(A M (p M )-A M (l M ,j))/(p M -l M ,j); (7) forming a sequence of V gradient differences z l ,j =B M ,l,j -B I ,l,j for j=1, . . . ,V; (8) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =K.sub.l (z.sub.l,1, . . . , z.sub.l,V), where K l is a selected function of V variables; and (9) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 34

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the correlation amplitude ratios r I ,e,i =A I (e I ,i)/A I (p I ) have selected values, and forming a first sequence of gradient values B I ,e,i =(A I (p I )-A I (e I ,i))/(p I -e I ,i); (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the correlation amplitude ratios r M ,e,i =A M (e M ,i)/A M (p M ) have selected values, and forming a second sequence of gradient values B M ,e,i =(A M (p M ) -A M (e M ,i))/(p M -e M ,i); (7) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; U+V≧1) for the first correlation function A I (t) for which the correlation amplitude ratios r I ,l,j =A I (l I ,j)/A I (p I ) have selected values and forming a sequence of gradient values B I ,l,j =(A I (p I )-A I (l I ,j))/(p I -l I ,j); (8) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the correlation amplitude ratios r M ,l,j =A M (l M ,l)/A M (p M ) have selected values, and forming a sequence of gradient values B M ,l,j =(A M (p M )-A M (l M ,j))/(p M -l M ,j); (9) forming a sequence of U gradient differences z e ,i =B M ,e,i -B I ,e,i for i=1, . . . , U; (10) forming a sequence of V gradient differences z l ,j =B M ,l,j -B I ,l,j for j=1, . . . , V; (11) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =K(z.sub.e,1, . . . , z.sub.e,U, z.sub.l,1, . . . , z.sub.l,V), where K is a selected function of U+V variables; and (12) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 35

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: (1) generating a first correlation function A I (t) representing a timing relationship between a selected reference signal and the reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; (2) receiving a distorted composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal; (3) generating a second correlation function A M (t) representing a timing relationship between the composite signal and the reference signal; (4) determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the second correlation function; (5) determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the correlation amplitude ratios r I ,e,i =A I (e I ,i)/A I (p I ) have selected values, and forming a first sequence of gradient values B I ,e,i =(A I (p I )-A I (e I ,i))/(p I -e I ,i); (6) determining a sequence of U early code phase shift values e M ,i <p M (i=1, . . . , U) for the second correlation function A M (t) for which the correlation amplitude ratios r M ,e,i =A M (e M ,i)/A M (p M ) have selected values, and forming a second sequence of gradient values B M ,e,i =(A M (p M ) -A M (e M ,i))/(p M -e M ,i); (7) determining a sequence of V late code phase shift values l I ,j >p I (j =1, . . . , V; U+V≧1) for the first correlation function A I (t) for which the correlation amplitude ratios r I ,l,j =A I (l I ,j)/A I (p I ) have selected values and forming a sequence of gradient values B I ,l,j =(A I (p I )-A I (l I ,j))/(p I -l I ,j); (8) determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the correlation amplitude ratios r M ,l,j =A M (l M ,l)/A M (p M ) have selected values, and forming a sequence of gradient values B M ,l,j =(A M (p M )-A M (l M ,j))/(p M -l M ,j); (9) forming a sequence of U gradient differences z e ,i =B M ,e,i -B I ,e,i for i=1, . . . , U; (10) forming a sequence of V gradient differences z l ,j =B M ,l,j -B I ,l,j for j=1, . . . , V; (11) determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =K(z.sub.e,1, . . . , z.sub.e,U, z.sub.l,1, . . . , z.sub.l,V), where K is a selected function of U+V variables; and (12) subtracting the difference p M -p I from an apparent time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 37

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: receiving a selected reference signal S ref (t) and generating an in-phase reference signal component S ref ,in-phase (t) and a quadrature reference signal component S ref ,quad (t) from this reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; receiving a composite signal S comp (t), consisting of a preferred, interference-free signal distorted by at least one interfering signal, and generating an in-phase reference signal component S comp ,in-phase (t) and a quadrature reference signal component S comp ,quad (t) from this composite signal; generating a first correlation function A I ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a second correlation function A M ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a third correlation function A I ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a fourth correlation function A M ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a first combined correlation function A.sub.I (t)=[(A.sub.I,in-phase (t)).sup.2 +(A.sub.I,quad (t)).sup.2 ].sup.1/2 ; generating a second combined correlation function A.sub.M (t)=[(A.sub.M,in-phase (t)).sup.2 +(A.sub.M,quad (t)).sup.2 ].sup.1/2 ; and determining a nominal peak amplitude A I (p I ) and the corresponding code phase shift value t=p I of the first combined correlation function; determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the first combined correlation function; determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift differences p I -e I ,i =Δ I ,e,i have selected values; determining a sequence of U early code phase shift values e M ,i <p M (i =1, . . . , U) for the second correlation function A M (t) for which the code phase shift differences p M -e M ,i =Δ M ,e,i have selected values; forming a sequence of U correlation amplitude ratios defined by the relations x e ,i =(A M (e M ,i)/A M (p M ))-(A I (e I ,i)/A I (p I )) for i=1, . . . , U; and determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =F.sub.e (x.sub.e,1, x.sub.e,2, . . . , x.sub.e,U), where F e is a selected function of U variables.

Claim 38

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: receiving a selected reference signal S ref (t) and generating an in-phase reference signal component S ref ,in-phase (t) and a quadrature reference signal component S ref ,quad (t) from this reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; receiving a composite signal S comp (t), consisting of a preferred, interference-free signal distorted by at least one interfering signal, and generating an in-phase reference signal component S comp ,in-phase (t) and a quadrature reference signal component S comp ,quad (t) from this composite signal; generating a first correlation function A I ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a second correlation function A M ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a third correlation function A I ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a fourth correlation function A M ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a first combined correlation function A.sub.I (t)=[(A.sub.I,in-phase (t)).sup.2 +(A.sub.I,quad (t)).sup.2 ].sup.1/2 ; generating a second combined correlation function A.sub.M (t)=[(A.sub.M,in-phase (t)).sup.2 +(A.sub.M,quad (t)).sup.2 ].sup.1/2 ; and determining a nominal peak amplitude A I (p I ) and the corresponding code phase shift value t=p I of the first combined correlation function; determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the first combined correlation function; determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift differences p I -e I ,i =Δ I ,e,i have selected values; determining a sequence of U early code phase shift values e M ,i <p M (i =1, . . . , U) for the second correlation function A M (t) for which the code phase shift differences p M -e M ,i =Δ M ,e,i have selected values; forming a sequence of U correlation amplitude ratios defined by the relations x e ,i =(A M (e M ,i)/A M (p M ))-(A I (e I ,i)/A I (p I )) for i=1, . . . , U; and determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =F.sub.e (x.sub.e,1, x.sub.e,2, . . . , x.sub.e,U), where F e is a selected function of U variables.

Claim 39

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: receiving a composite signal S comp (t), consisting of a preferred, interference-free signal distorted by at least one interfering signal, and generating an in-phase reference signal component S comp ,in-phase (t) and a quadrature reference signal component S comp ,quad (t) from this composite signal; generating a first correlation function A I ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a second correlation function A M ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a third correlation function A I ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a fourth correlation function A M ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a first combined correlation function A.sub.I (t)=[(A.sub.I,in-phase (t)).sup.2 +(A.sub.I,quad (t)).sup.2 ].sup.1/2 ; generating a second combined correlation function A.sub.M (t)=[(A.sub.M,in-phase (t)).sup.2 +(A.sub.M,quad (t)).sup.2 ].sup.1/2 ; and determining a nominal peak amplitude A I (p I ) and the corresponding code phase shift value t=p I of the first combined correlation function; determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the first combined correlation function; determining a sequence of V late code phase shift values l I ,j >p I (j=1, . . . , V; V≧1) for the first correlation function A I (t) for which the code phase shift differences p I -l I ,j =Δ I ,l,j have selected values; determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift differences p M -l M ,i =Δ M ,l,j have selected values; forming a sequence of V correlation amplitude ratios defined by the relations x l ,i =(A M (l M ,j)/A M (p M ))-(A I (l I ,j)/A I (p I )) for j=1, . . . , V; determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =F.sub.l (x.sub.l,1, x.sub.l,2, . . . , x.sub.l,V), where F l is a selected function of V variables; and subtracting the difference p M -p I from an apparent, time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 40

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: receiving a composite signal S comp (t), consisting of a preferred, interference-free signal distorted by at least one interfering signal, and generating an in-phase reference signal component S comp ,in-phase (t) and a quadrature reference signal component S comp ,quad (t) from this composite signal; generating a first correlation function A I ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a second correlation function A M ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a third correlation function A I ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a fourth correlation function A M ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a first combined correlation function A.sub.I (t)=[(A.sub.I,in-phase (t)).sup.2 +(A.sub.I,quad (t)).sup.2 ].sup.1/2 ; generating a second combined correlation function A.sub.M (t)=[(A.sub.M,in-phase (t)).sup.2 +(A.sub.M,quad (t)).sup.2 ].sup.1/2 ; and determining a nominal peak amplitude A I (p I ) and the corresponding code phase shift value t=p I of the first combined correlation function; determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the first combined correlation function; determining a sequence of V late code phase shift values l I ,j >p I (j=1, . . . , V; V≧1) for the first correlation function A I (t) for which the code phase shift differences p I -l I ,j =Δ I ,l,j have selected values; determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift differences p M -l M ,i =Δ M ,l,j have selected values; forming a sequence of V correlation amplitude ratios defined by the relations x l ,i =(A M (l M ,j)/A M (p M ))-(A I (l I ,j)/A I (p I )) for j=1, . . . , V; determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =F.sub.l (x.sub.l,1, x.sub.l,2, . . . , x.sub.l,V), where F l is a selected function of V variables; and subtracting the difference p M -p I from an apparent, time of arrival of the composite code phase SATPS signal to redetermine the time of arrival of this signal.

Claim 41

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: receiving a selected reference signal S ref (t) and generating an in-phase reference signal component S ref ,in-phase (t) and a quadrature reference signal component S ref ,quad (t) from this reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; receiving a composite signal S comp (t), consisting of a preferred, interference-free signal distorted by at least one interfering signal, and generating an in-phase reference signal component S comp ,in-phase (t) and a quadrature reference signal component S comp ,quad (t) from this composite signal; generating a first correlation function A I ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a second correlation function A M ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a third correlation function A I ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a fourth correlation function A M ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a first combined correlation function A.sub.I (t)=[(A.sub.I,in-phase (t)).sup.2 +(A.sub.I,quad (t)).sup.2 ].sup.1/2 ; generating a second combined correlation function A.sub.M (t)=[(A.sub.M,in-phase (t)).sup.2 +(A.sub.M,quad (t)).sup.2 ].sup.1/2 ; and determining a nominal peak amplitude A I (p I ) and the corresponding code phase shift value t=p I of the first combined correlation function; determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the first combined correlation function; determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (e I ,i)/A I (p I )=r I ,e,i have selected values; determining a sequence of U early code phase shift values e M ,i <p M (i =1, . . . , U) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (e M ,i)/A M (p M )=r M ,e,i have selected values; forming a sequence of U code phase shift differences defined by the relations y e ,i =(p M -e M ,i)-(p I -e I ,i) for i=1, . . . , U; and determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =G.sub.e (y.sub.e,1, y.sub.e,2, . . . , y.sub.e,U), where G e is a selected function of U variables.

Claim 42

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: receiving a selected reference signal S ref (t) and generating an in-phase reference signal component S ref ,in-phase (t) and a quadrature reference signal component S ref ,quad (t) from this reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; receiving a composite signal S comp (t), consisting of a preferred, interference-free signal distorted by at least one interfering signal, and generating an in-phase reference signal component S comp ,in-phase (t) and a quadrature reference signal component S comp ,quad (t) from this composite signal; generating a first correlation function A I ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a second correlation function A M ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a third correlation function A I ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a fourth correlation function A M ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a first combined correlation function A.sub.I (t)=[(A.sub.I,in-phase (t)).sup.2 +(A.sub.I,quad (t)).sup.2 ].sup.1/2 ; generating a second combined correlation function A.sub.M (t)=[(A.sub.M,in-phase (t)).sup.2 +(A.sub.M,quad (t)).sup.2 ].sup.1/2 ; and determining a nominal peak amplitude A I (p I ) and the corresponding code phase shift value t=p I of the first combined correlation function; determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the first combined correlation function; determining a sequence of U early code phase shift values e I ,i <p I (i=1, . . . , U; U≧1) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (e I ,i)/A I (p I )=r I ,e,i have selected values; determining a sequence of U early code phase shift values e M ,i <p M (i =1, . . . , U) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (e M ,i)/A M (p M )=r M ,e,i have selected values; forming a sequence of U code phase shift differences defined by the relations y e ,i =(p M -e M ,i)-(p I -e I ,i) for i=1, . . . , U; and determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =G.sub.e (y.sub.e,1, y.sub.e,2, . . . , y.sub.e,U), where G e is a selected function of U variables.

Claim 43

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: receiving a selected reference signal S ref (t) and generating an in-phase reference signal component S ref ,in-phase (t) and a quadrature reference signal component S ref ,quad (t) from this reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; receiving a composite signal S comp (t), consisting of a preferred, interference-free signal distorted by at least one interfering signal, and generating an in-phase reference signal component S comp ,in-phase (t) and a quadrature reference signal component S comp ,quad (t) from this composite signal; generating a first correlation function A I ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a second correlation function A M ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a third correlation function A I ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a fourth correlation function A M ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a first combined correlation function A.sub.I (t)=[(A.sub.I,in-phase (t)).sup.2 +(A.sub.I,quad (t)).sup.2 ].sup.1/2 ; generating a second combined correlation function A.sub.M (t)=[(A.sub.M,in-phase (t)).sup.2 +(A.sub.M,quad (t)).sup.2 ].sup.1/2 ; and determining a nominal peak amplitude A I (p I ) and the corresponding code phase shift value t=p I of the first combined correlation function; determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the first combined correlation function; determining a sequence of V late code phase shift values l I ,j >p I (j=1, . . . , V; V≧1) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (l I ,j)/A I (p I )=r I ,e,j have selected values; determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (l M ,j)/A M (p M )=r M ,l,j have selected values; forming a sequence of V code phase shift differences defined by the relations y l ,j =(p M -l M ,j)-(p I -l I ,j) for j=1, . . . , V; and determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =G.sub.l (y.sub.l,1, y.sub.l,2, . . . , y.sub.l,V), where G l is a selected function of V variables.

Claim 44

A method of synchronizing to a reference signal the timing of a received composite, code phase SATPS signal, the composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing point of the preferred signal, the method comprising the steps of: receiving a selected reference signal S ref (t) and generating an in-phase reference signal component S ref ,in-phase (t) and a quadrature reference signal component S ref ,quad (t) from this reference signal, where the reference signal is a digital signal with a timing cycle of selected length, and where A I (t) has a peak amplitude at an unknown code phase shift value t=p I ; receiving a composite signal S comp (t), consisting of a preferred, interference-free signal distorted by at least one interfering signal, and generating an in-phase reference signal component S comp ,in-phase (t) and a quadrature reference signal component S comp ,quad (t) from this composite signal; generating a first correlation function A I ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a second correlation function A M ,in-phase (t) representing a timing relationship between the signal S ref ,in-phase (t) and the signal S comp ,in-phase (t); generating a third correlation function A I ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a fourth correlation function A M ,quad (t) representing a timing relationship between the signal S ref ,quad (t) and the signal S comp ,quad (t); generating a first combined correlation function A.sub.I (t)=[(A.sub.I,in-phase (t)).sup.2 +(A.sub.I,quad (t)).sup.2 ].sup.1/2 ; generating a second combined correlation function A.sub.M (t)=[(A.sub.M,in-phase (t)).sup.2 +(A.sub.M,quad (t)).sup.2 ].sup.1/2 ; and determining a nominal peak amplitude A I (p I ) and the corresponding code phase shift value t=p I of the first combined correlation function; determining a nominal peak amplitude A M (p M ) and the corresponding code phase shift value t=p M of the first combined correlation function; determining a sequence of V late code phase shift values l I ,j >p I (j=1, . . . , V; V≧1) for the first correlation function A I (t) for which the code phase shift amplitude ratios A I (l I ,j)/A I (p I )=r I ,e,j have selected values; determining a sequence of V late code phase shift values l M ,j >p M (j=1, . . . , V) for the second correlation function A M (t) for which the code phase shift amplitude ratios A M (l M ,j)/A M (p M )=r M ,l,j have selected values; forming a sequence of V code phase shift differences defined by the relations y l ,j =(p M -l M ,j)-(p I -l I ,j) for j=1, . . . , V; and determining the difference in punctual code phase shift between the first and second correlation functions by the relation p.sub.M -p.sub.I =G.sub.l (y.sub.l,1, y.sub.l,2, . . . , y.sub.l,V), where G l is a selected function of V variables.