US6259404B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Position location system and method
Assignee: Signatron Tech Corp
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Filing: 1999-03-15
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Granted: 2001-07-10
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Expires: 2019-03-15
Abstract
Abstract A position location system includes multiple base stations spaced over a region. A remote unit within the region transmits a locating signal which is received by the base stations. The base stations report amplitude, phase and time data related to the locating signal to a control station. The control station includes a processor and memory that combine the data from all of the participating base stations to directly compute an optimal estimate of the location of the portable unit. The control station generates a locator function based upon the probability that the portable unit is located at a particular position. By optimizing the locator function, the error in the computation is minimized to produce an accurate position estimate.
Inventors
- 👤 Steen A. Parl
- 👤 Julian Bussgang
- 👤 Jay Weitzen
- 👤 James M. Zagami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:40
CPC Classifications
G; G01; G01S; G01S5/00; G01S5/02; G01S5/06; G01S1/00; G01S1/02; G01S1/04; G01S1/045
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
140 words
A position location system comprising: a transmitting unit comprising a transmitter that transmits a locating signal composed of multiple tones; at least three antennas located at at least two base stations which receive the locating signal; at least one receiver coupled to each antenna that generates representative complex signals indicative of amplitude and phase of at least two selected tone components of the locating signal as received at the corresponding antenna, the receiver also generating values indicative of the frequencies of received tone components; and a processor that receives the representative complex signals from the antenna and uses the amplitude and phase information in said representative complex signals and the generated frequency values to define a locator function for the transmitting unit, and determines estimated location coordinates for the transmitting unit that generate a maximum value of the locator function.
Claim 2
Dependent Claim
140 words
A position location system comprising: a transmitting unit comprising a transmitter that transmits a locating signal composed of multiple tones; at least three antennas located at at least two base stations which receive the locating signal; at least one receiver coupled to each antenna that generates representative complex signals indicative of amplitude and phase of at least two selected tone components of the locating signal as received at the corresponding antenna, the receiver also generating values indicative of the frequencies of received tone components; and a processor that receives the representative complex signals from the antenna and uses the amplitude and phase information in said representative complex signals and the generated frequency values to define a locator function for the transmitting unit, and determines estimated location coordinates for the transmitting unit that generate a maximum value of the locator function.
Claim 3
Dependent Claim
31 words
The position location system of claim 1 wherein the processor uses the received values indicative of the frequencies to eliminate frequency offsets of the transmitting unit to estimate location more accurately.
Claim 4
Dependent Claim
28 words
The position location system of claim 1 wherein the processor uses the received values indicative of the frequencies to estimate both motion and velocity of the transmitting unit.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-07-09 | 2005-01-08 | 2005-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-07-09 | 2009-01-08 | 2009-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-07-09 | 2013-01-08 | 2013-07-10 | $7700.00 | Window Closed / Lapsed |