Code multipath error estimation using weighted correlations
First Claim
Patent Images
1. An apparatus for use in decoding a composite signal (CS) that includes a distortion component, said apparatus comprising:
- an input means for down converting to baseband an input satellite signal;
a first reference means for generating a first reference signal;
a first weighting means connected to said first reference means for generating a time varying first weighting signal, wherein said first weighting signal is mixed with said composite signal and with said first reference signal;
a first correlation means connected to said first weighting means for generating a first correlation signal, wherein said first correlation signal includes a suppressed distortion component, and wherein said first correlation signal includes a residual distortion component;
a second reference means connected to said input circuit for generating a second reference signal;
a second weighting means connected to said second reference means for generating a time varying second weighting signal, wherein said second weighting signal is mixed with said composite signal and with said second reference signal;
a second correlation means connected to said second weighting means for generating a second correlation signal; and
a computer means connected to said first correlation means and connected to said second correlation means for closing the code and carrier tracking loops, for actual estimation of said residual distortion signal in said first correlation signal, and for actual minimization of said residual distortion signal in said first correlation signal.
3 Assignments
0 Petitions
Accused Products
Abstract
The apparatus and method for minimization the residual multipath distortion signal present in the received spread spectrum signal are disclosed. In the preferred embodiment, the apparatus comprises a generator of non-uniform weighting function used for estimation and actual minimization of the residual multipath signal.
-
Citations
28 Claims
-
1. An apparatus for use in decoding a composite signal (CS) that includes a distortion component, said apparatus comprising:
-
an input means for down converting to baseband an input satellite signal; a first reference means for generating a first reference signal; a first weighting means connected to said first reference means for generating a time varying first weighting signal, wherein said first weighting signal is mixed with said composite signal and with said first reference signal; a first correlation means connected to said first weighting means for generating a first correlation signal, wherein said first correlation signal includes a suppressed distortion component, and wherein said first correlation signal includes a residual distortion component; a second reference means connected to said input circuit for generating a second reference signal; a second weighting means connected to said second reference means for generating a time varying second weighting signal, wherein said second weighting signal is mixed with said composite signal and with said second reference signal; a second correlation means connected to said second weighting means for generating a second correlation signal; and a computer means connected to said first correlation means and connected to said second correlation means for closing the code and carrier tracking loops, for actual estimation of said residual distortion signal in said first correlation signal, and for actual minimization of said residual distortion signal in said first correlation signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. An apparatus for use in decoding a composite signal (CS) that includes a transmitted direct signal (DS) and at least one multipath noise signal (MS), said apparatus comprising
a channel A means further comprising: -
an input (A) means for down converting to baseband an input satellite signal; a reference (A) means for generating a reference (A) signal; a correlator (A) means connected to said reference (A) means and connected to said input (A) means for generating a correlation (A) signal; a channel B means further comprising; an input (B) means for down converting to baseband an input satellite signal; a reference (B) means for generating a reference (B) signal; a correlator (B) means connected to said reference (B) means and connected to said input (B) means for generating a correlation (B) signal, wherein said correlation (B) signal is used to minimize said distortion multipath component signal and said residual distortion multipath component signal; and a computer means connected to said channel A means and connected to said channel B means for performing the control function of said A channel means and said B channel means. - View Dependent Claims (13, 14, 15, 16, 17, 18)
-
-
19. An apparatus for use in decoding a composite signal (CS) that includes a transmitted direct signal (DS) and at least one multipath noise signal (MS), said apparatus comprising:
-
an input means for down converting an input satellite signal to a baseband signal; a reference means for generating a reference signal; a multiple time shifted replicas means connected to said reference means for generating a plurality of time shifted replicas of said reference signal, wherein each said time shifted replica signal has its own delay as compared with said reference signal; a mixing and despreading means connected to said multiple time shifted replicas means for mixing said baseband signal with each said time shifted replica signal and for generating a plurality of mix and despread signals; a correlation means connected to said mixing and despreading means for processing each said mix and despread signal and for generating a correlation signal; and a computer means connected to said input means, connected to said reference means, and connected to said correlation means for closing the code and carrier tracking loops, for minimizing said distortion component multipath signal, and for estimation and minimization of said residual distortion multipath signal. - View Dependent Claims (20)
-
-
21. An apparatus for use in decoding a composite signal (CS) that includes a transmitted direct signal (DS) and at least one multipath noise signal (MS), said apparatus comprising:
-
an input means for down converting an input satellite signal to a baseband signal; a reference means for generating a reference signal; a multiple time shifted replicas means connected to said reference means for generating a plurality of time shifted replicas of said reference signal, wherein each said time shifted replica signal has its own delay as compared with said reference signal; a mixing and despreading means connected to said multiple time shifted replicas means for mixing said baseband signal with each said time shifted replica signal and for generating a plurality of mix and despread signals; an Early and Late weighting means connected to said multiple time shifted replicas means for generating time varying Early and Late weighting signals, wherein said Early and Late weighting signals are mixed with each said time shifted replicas of said reference signal; a tracking correlation means connected to said Early and Late weighting means for generating a tracking correlation signal, wherein said tracking correlation signal includes a suppressed distortion component and a residual distortion component; an estimation weighting means connected to said multiple time shifted replicas means said for generating at least one time varying estimation weighting signal, wherein at least one said estimation weighting signal is mixed with each said time shifted replicas of said reference signal; an estimation correlation means connected to said estimation weighting means for generating at least one estimation correlation signal; and a computer means connected to said tracking correlation means and connected to said estimation correlation means for closing the code and carrier tracking loops, for actual estimation of said residual distortion signal in said tracking correlation signal with a suppressed distortion component, and for actual minimization of said residual distortion signal in said tracking correlation signal. - View Dependent Claims (22, 23, 24)
-
-
25. A method for decoding a composite signal (CS) that includes a distortion component, said method comprising the steps of:
-
down converting to baseband an input satellite signal by an input means; generating a first reference signal by a first reference means; generating a time varying first weighting signal by a first weighting means;
wherein said first weighting signal is mixed with said composite signal and with said first reference signal;generating a first correlation signal by a first correlation means, wherein said first correlation signal includes a suppressed distortion component, and wherein said first correlation signal includes a residual distortion component; generating a second reference signal by a second reference means; generating a time varying second weighting signal by a second weighting means, wherein said second weighting signal is mixed with said composite signal and with said second reference signal; generating a second correlation signal by a second correlation means; and closing the code and carrier tracking loops, actually estimating said residual distortion signal in said first correlation signal, and actually minimizing said residual distortion signal in said first correlation signal by a computer means.
-
-
26. A method for decoding a composite signal (CS) that includes a transmitted direct signal (DS) and at least one multipath noise signal (MS), said method comprising the steps of:
-
down converting to baseband an input satellite signal by an input (A) means; generating a reference (A) signal by a reference (A) means; generating a correlation (A) signal by a correlator (A) means; down converting to baseband an input satellite signal by an input (B) means; generating a reference (B) signal by a reference (B) means; generating a correlation (B) signal by a correlator (B) means, wherein said correlation (B) signal is used to minimize said distortion multipath component signal and said residual distortion multipath component signal; and performing the control function of said A channel means and said B channel means by a computer means.
-
-
27. A method for decoding a composite signal (CS) that includes a transmitted direct signal (DS) and at least one multipath noise signal (MS), said method comprising the steps of:
-
down converting an input satellite signal to a baseband signal by an input means; generating a reference signal by a reference means; generating a plurality of time shifted replicas of said reference signal by a multiple time shifted replicas means, wherein each said time shifted replica signal has its own delay as compared with said reference signal; mixing said baseband signal with each said time shifted replica signal and generating a plurality of mix and despread signals by a mixing and despreading means; processing each said mix and despread signal and generating a correlation signal by a correlation means; closing the code and carrier tracking loops by a computer means; obtaining a suppressed distortion multipath signal; and estimating and minimizing a residual distortion multipath signal by said computer means.
-
-
28. A method for decoding a composite signal (CS) that includes a transmitted direct signal (DS) and at least one multipath noise signal (MS), said method comprising the steps of:
-
down converting an input satellite signal to a baseband signal by an input means; generating a reference signal by a reference means; generating a plurality of time shifted replicas of said reference signal by a multiple time shifted replicas means, wherein each said time shifted replica signal has its own delay as compared with said reference signal; mixing said baseband signal with each said time shifted replica signal and generating a plurality of mix and despread signals by a mixing and despreading means; generating time varying Early and Late weighting signals by an Early and Late weighting means;
wherein said Early and Late weighting signals are mixed with each said time shifted replicas of said reference signal;generating a tracking correlation signal by a tracking correlation means, wherein said tracking correlation signal includes a suppressed distortion component and a residual distortion component; generating at least one time varying estimation weighting signal by an estimation weighting means, wherein at least one said estimation weighting signal is mixed with each said time shifted replicas of said reference signal; generating at least one estimation correlation signal by an estimation correlation means; closing the code and carrier tracking loops by a computer means; obtaining a suppressed multipath signal; actually estimating said residual distortion signal in said tracking correlation signal by said computer means; and actually minimizing said residual distortion signal in said tracking correlation signal by said computer means.
-
Specification