US5815539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal timing synchronizer
Assignee: Trimble Inc
•
Filing: 1996-07-12
•
Granted: 1998-09-29
•
Expires: 2016-07-12
Abstract
Abstract A method and apparatus are disclosed for characterizing multipath-induced distortions in the autocorrelation function of a correlation receiver in order to reduce effects of these multipath-induced distortions on the accuracy of detecting the time of arrival of a received signal. The magnitude of the multipath-induced errors adversely affecting the shape of the autocorrelation function is estimated in real time, for example, through the use of secondary scanning correlators whose time base is independent of a typical receiver's detection-oriented correlators. This error is subtracted from the detection-oriented correlator's timing, thereby yielding a more accurate autocorrelation function.
Inventors
- 👤 Gary R. Lennen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 23:21
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/69; H04B1/707; H04B1/7073; H04B1/7085; G; G01; G01S; G01S19/00; G01S19/01; G01S19/13; G01S19/22; G01S19/24; G01S19/30; H04B1/709; G01S19/35; G01S19/37
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
162 words
A method of synchronizing to a reference signal the timing of a received composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing of the preferred signal, the method comprising the steps of: generating points on a correlation function representative of a timing relationship between the distorted composite signal and the reference signal; determining a nominal peak amplitude and the location in time of the nominal peak amplitude of said correlation function; determining the location in time and amplitude of a first point that is displaced from said nominal peak on said correlation function relative to said nominal peak; determining the location in time and amplitude of a second point that is displaced from said first point; determining a displacement of said first point relative to said second point; and identifying said displacement with the displacement in time required to synchronize the timing of the reference signal to said received composite signal.
Claim 2
Independent Claim
162 words
A method of synchronizing to a reference signal the timing of a received composite signal consisting of a preferred, interference-free signal distorted by at least one interfering signal, to determine an undistorted timing of the preferred signal, the method comprising the steps of: generating points on a correlation function representative of a timing relationship between the distorted composite signal and the reference signal; determining a nominal peak amplitude and the location in time of the nominal peak amplitude of said correlation function; determining the location in time and amplitude of a first point that is displaced from said nominal peak on said correlation function relative to said nominal peak; determining the location in time and amplitude of a second point that is displaced from said first point; determining a displacement of said first point relative to said second point; and identifying said displacement with the displacement in time required to synchronize the timing of the reference signal to said received composite signal.
Claim 3
Dependent Claim
22 words
The method of claim 1, wherein said displacement of said first point relative to said second point is a displacement in time.
Claim 4
Dependent Claim
22 words
The method of claim 1, wherein said displacement of said first point relative to said second point is a displacement in amplitude.
Claim 5
Dependent Claim
31 words
The method of claim 3, further comprising the step of choosing said first point and said second point to have an amplitude which is a fraction of said nominal peak amplitude.
Claim 6
Dependent Claim
16 words
The method of claim 4, wherein said fraction is within the range of 0.55 to 0.70.
Claim 7
Dependent Claim
10 words
The method of claim 5, wherein said fraction is 0.65.
Claim 8
Dependent Claim
47 words
The method of claim 1, wherein: said location in time of said first point is less than said location in time of said nominal peak amplitude; and said location in time of said second point is greater than said location in time of said nominal peak amplitude.
Claim 9
Dependent Claim
180 words
Apparatus for synchronizing to a reference signal the timing of a received composite signal including a preferred, interference-free signal and at least one interfering signal, the apparatus comprising: correlation means for generating points on a correlation function that represents the timing relationship between a reference signal and the composite signal and for determining an amplitude of the nominal peak of the correlation function and a location in time of the nominal peak; measurement means for determining the locations in time and amplitudes of at least first and second points on said correlation function, the locations in time being positioned respectively on opposite sides of the location in time of said nominal peak and having respective amplitudes equal to respective fractions of the amplitude of said nominal peak and for determining a first difference between the said first and second points; displacement means for determining a second difference of said first difference and a selected constant and for identifying said second difference with the displacement in time required to synchronize the timing of said reference signal with said received composite signal.
Claim 10
Dependent Claim
180 words
Apparatus for synchronizing to a reference signal the timing of a received composite signal including a preferred, interference-free signal and at least one interfering signal, the apparatus comprising: correlation means for generating points on a correlation function that represents the timing relationship between a reference signal and the composite signal and for determining an amplitude of the nominal peak of the correlation function and a location in time of the nominal peak; measurement means for determining the locations in time and amplitudes of at least first and second points on said correlation function, the locations in time being positioned respectively on opposite sides of the location in time of said nominal peak and having respective amplitudes equal to respective fractions of the amplitude of said nominal peak and for determining a first difference between the said first and second points; displacement means for determining a second difference of said first difference and a selected constant and for identifying said second difference with the displacement in time required to synchronize the timing of said reference signal with said received composite signal.
Claim 11
Dependent Claim
17 words
The apparatus of claim 8, wherein said first difference and said second difference are differences in time.
Claim 12
Dependent Claim
17 words
The apparatus of claim 8, wherein said first difference and said second difference are differences in amplitude.
Claim 13
Dependent Claim
16 words
The apparatus of claim 8, wherein said fractions are within the range of 0.55 to 0.70.
Claim 14
Dependent Claim
10 words
The apparatus of claim 8, wherein said fractions are 0.65.
Claim 15
Dependent Claim
165 words
Apparatus for synchronizing to a reference signal the timing of a received composite signal, including a preferred, interference-free signal and at least one interfering signal, to determine an undistorted timing of the preferred signal, the apparatus comprising: correlation means for generating points on a correlation function that represents a timing relationship between said received composite signal and the reference signal, and for determining an amplitude of a nominal peak of the correlation function and a location in time of the nominal peak; measurement means for determining at least a first point on said correlation function that has an amplitude equal to a fraction of the amplitude of said nominal peak and for determining a first difference between said nominal peak and said first point; and displacement means for determining a second difference between said first difference and a selected constant and for identifying said second difference with the displacement in time required to synchronize the timing of said reference signal with said received composite signal.
Claim 16
Dependent Claim
165 words
Apparatus for synchronizing to a reference signal the timing of a received composite signal, including a preferred, interference-free signal and at least one interfering signal, to determine an undistorted timing of the preferred signal, the apparatus comprising: correlation means for generating points on a correlation function that represents a timing relationship between said received composite signal and the reference signal, and for determining an amplitude of a nominal peak of the correlation function and a location in time of the nominal peak; measurement means for determining at least a first point on said correlation function that has an amplitude equal to a fraction of the amplitude of said nominal peak and for determining a first difference between said nominal peak and said first point; and displacement means for determining a second difference between said first difference and a selected constant and for identifying said second difference with the displacement in time required to synchronize the timing of said reference signal with said received composite signal.
Claim 17
Dependent Claim
17 words
The apparatus of claim 13, wherein said first difference and said second difference are differences in time.
Claim 18
Dependent Claim
17 words
The apparatus of claim 13, wherein said first difference and said second difference are differences in amplitude.
Claim 19
Dependent Claim
16 words
The apparatus of claim 13, wherein said fractions are within the range of 0.55 to 0.70.
Claim 20
Dependent Claim
10 words
The apparatus of claim 13, wherein said fractions are 0.65.
References Cited (Backward Citations)
US4545061A
Cited
US4628320A
Cited
US3915090A
Cited
US4203070A
Cited
US4426712A
Cited
US4457006A
Cited
US4521111A
Cited
US4530103A
Cited
US4706286A
Cited
GB2155268A
Cited
EP0166911A2
Cited
US4754465A
Cited
EP0166300A2
Cited
US4611333A
Cited
US4785463A
Cited
US4807256A
Cited
US4800577A
Cited
US4791378A
Cited
US4821294A
Cited
EP0312193A2
Cited
US4894842A
Cited
US4829543A
Cited
US5157695A
Cited
GB2215539A
Cited
US5016257A
Cited
US4847862A
Cited
EP0336418A2
Cited
EP0351156A1
Cited
US5070536A
Cited
US5483676A
Cited
US4910794A
Cited
US4932036A
Cited
EP0460862A2
Cited
US5101416A
Cited
EP0488739A1
Cited
US5495499A
Cited
US5390207A
Cited
US5148452A
Cited
US5245472A
Cited
US5414729A
Cited
US5285472A
Cited
US5528635A
Cited
US5598429A
Cited
US5566202A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-09-28 | 2002-03-30 | 2002-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-28 | 2006-03-30 | 2006-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-28 | 2010-03-30 | 2010-09-29 | $7700.00 | Window Closed / Lapsed |