Patent US5600706A successfully refreshed from Google Patents.
US5600706A
Expired / Lapsed
US
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Method and system for determining the position of a mobile receiver
Assignee: Comcast MO Group Inc
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Filing: 1994-05-09
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Granted: 1997-02-04
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Expires: 2014-05-09
Abstract
Abstract A position system and method utilizes a plurality of range transceivers located at known fixed locations and which are adapted to transmit approximately synchronized digital range signals for receipt by both a primary receiver and a supplemental receiver, the former disposed at a known location and the latter disposed at an unknown location. The range transceivers are adapted to transmit pulse sequences which include an error portion corresponding to the approximate synchronization error of each range signal. This error portion is constantly updated in accordance with the last determined synchronization errors of the corresponding range signals received by a secondary transceiver. In an alternative embodiment employing Code Division Multiple Access (CDMA) technology, the range transceiver time stamp on transmitted range signals may be adjusted to account for the measured timing error for a given range transceiver. The supplemental receiver receives the range signals and uses the same in accordance with known time of arrival or time difference of arrival calculation techniques to determine the position of the supplemental receiver.
Inventors
- 👤 Michael J. Dunn
- 👤 Don H. Atherly
- 👤 Douglas O. J. Reudink
- 👤 Martin J. Feuerstein
- 👤 Ronald E. Foerster
- 👤 Ching Chuang
- 👤 Dino J. Vendetti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:27
CPC Classifications
G; G01; G01S; G01S5/00; G01S5/02; G01S5/14; G01S5/10; H; H04; H04M; H04M15/00; H04M15/80; H04M15/8033; H04M15/8083; H04W; H04W4/00; H04W4/24; H04W60/00; H04M2215/00; H04M2215/01; H04M2215/0184; H04M2215/32; H04M2215/74; H04M2215/7435; H04W4/02; H04W64/00
Claims Analysis
Total Claims: 63
Claim 1
Independent Claim
146 words
A positioning system, comprising: a plurality of range transceivers at known fixed locations each having a time reference base for transmitting approximately synchronized digital range signals having a signal energy; at least one primary receiver each disposed at a known location relative to the locations of said plurality of range transceivers which (a) receives the digital range signals, (b) determines a deviation representing the amount that each digital range signal deviates from system synchronization, and (c) sends corresponding error signals to said plurality of range transceivers so as to more closely bring said digital range signals into synchronization; a supplemental receiver at an unknown location which receives said synchronized digital range signals; and computation means, in communication with the supplemental receiver, for computing, based on the time difference of arrival of the received synchronized digital range signals, coordinate values defining the position of said supplemental receiver.
Claim 2
Dependent Claim
146 words
A positioning system, comprising: a plurality of range transceivers at known fixed locations each having a time reference base for transmitting approximately synchronized digital range signals having a signal energy; at least one primary receiver each disposed at a known location relative to the locations of said plurality of range transceivers which (a) receives the digital range signals, (b) determines a deviation representing the amount that each digital range signal deviates from system synchronization, and (c) sends corresponding error signals to said plurality of range transceivers so as to more closely bring said digital range signals into synchronization; a supplemental receiver at an unknown location which receives said synchronized digital range signals; and computation means, in communication with the supplemental receiver, for computing, based on the time difference of arrival of the received synchronized digital range signals, coordinate values defining the position of said supplemental receiver.
Claim 3
Dependent Claim
15 words
A positioning system as in claim 1 wherein said digital range signals are pulse sequences.
Claim 4
Dependent Claim
18 words
A positioning system as in claim 2 wherein said pulse sequences are multiple sequential or interleaved "Barker Codes."
Claim 5
Dependent Claim
17 words
A positioning system as in claim 2 wherein said pulse sequences are Pseudo Random Noise (PN) sequences.
Claim 6
Dependent Claim
23 words
A positioning system as in claim 4 wherein said PN sequences have a unique code phase offset used to identify the range transceiver.
Claim 7
Dependent Claim
22 words
A positioning system as in claim 1 wherein said primary receiver is adapted to send said error signals via RF communication link.
Claim 8
Dependent Claim
22 words
A positioning system as in claim 1 wherein said primary receiver is adapted to send said error signals via direct electrical communication.
Claim 9
Dependent Claim
91 words
A positioning system as in claim 1 wherein each of said at least one primary receiver further comprises: a time detection device which detects and decodes said digital range signals; a precision time reference generated locally or received from a central source, said precision time reference having a selected accuracy sufficient for desired system tolerances; and a controller in electrical communication with said time detection device and said precision time reference which compares said decoded digital range signals with said precision time reference to determine the deviation from the system synchronization.
Claim 10
Dependent Claim
29 words
A positioning system as in claim 1 wherein the plurality of range transceivers are adapted to transmit said digital range signals sequentially in time using a time slotted protocol.
Claim 11
Dependent Claim
19 words
A positioning system as in claim 5 wherein the plurality of range transceivers transmit said digital range signals simultaneously.
Claim 12
Dependent Claim
32 words
A positioning system as in claim 10 wherein said supplemental receiver is adapted to compare said received digital range signals having known code phase offsets with a predetermined list of valid offsets.
Claim 13
Dependent Claim
37 words
A positioning system as in claim 1 wherein said supplemental receiver ranks said digital range signals based on a weighted combination of the signal energy of said digital range signal and the location of said range transceivers.
Claim 14
Dependent Claim
32 words
A positioning system as in claim 10 wherein the plurality of said range transceivers are further adapted to transmit said digital range signals on the same frequency so as to conserve bandwidth.
Claim 15
Dependent Claim
37 words
A positioning system as in claim 13 wherein said supplemental receiver receives said digital range signals over an interval of time sufficient to overcome a degradation in signal to interference ratio on signals from distant range transceivers.
Claim 16
Dependent Claim
45 words
A positioning system as in claim 13 wherein said supplemental receiver receives said digital range signals having code phase offsets selected to provide low autocorrelation sufficient to overcome a degradation in signal to interference ratio on said digital range signals received from distant range transceivers.
Claim 17
Dependent Claim
35 words
A positioning system as in claim 13 wherein said supplemental receiver has a dynamic range sufficient to overcome a degradation in signal to interference ratio on said digital range signals received from distant range transceivers.
Claim 18
Dependent Claim
21 words
A positioning system as in claim 13 wherein said supplemental receiver receives said digital range signals during a gated scanning period.
Claim 19
Dependent Claim
18 words
A positioning system as in claim 17 wherein said gated scanning period includes a narrow rotating null beam.
Claim 20
Dependent Claim
18 words
A positioning system as in claim 17 wherein said gated scanning period includes a narrow rotating fan beam.
Claim 21
Dependent Claim
37 words
A positioning system as in claim 13 wherein said plurality of range transceivers are each adapted to transmit a time stamp within said digital range signal, said time stamp adjusted by said range transceiver to simulate synchronization.
Claim 22
Dependent Claim
38 words
A positioning system as in claim 20 wherein said adjustments to said time stamps correspond to the last determined deviation from the system synchronization of the corresponding digital range signals received by said at least one primary receiver.
Claim 23
Dependent Claim
44 words
A positioning system as in claim 1 wherein said plurality of range transceivers are further adapted to receive said error signals and correspondingly adjust the output of the next transmitted digital range signal so as to drive the detected synchronization error to approximately zero.
Claim 24
Dependent Claim
39 words
A positioning system as in claim 1 wherein said plurality of range transceivers are each adapted to transmit multiple pulse sequences, said pulse sequences including an error portion corresponding to the approximate synchronization error of each digital range signal.
Claim 25
Dependent Claim
43 words
A positioning system as in claim 23 wherein the error portions of said pulse sequences generated by said plurality of range transceivers correspond to the last determined synchronization errors of the corresponding digital range signals received by said at least one primary receiver.
Claim 26
Dependent Claim
31 words
A positioning system as in claim 1 wherein said computation means is adapted to determine the time difference of arrival of said digital range signals in accordance with hyperbolic multilateration techniques.
Claim 27
Dependent Claim
30 words
A positioning system as in claim 1 wherein said computation means is adapted to determine the absolute time of arrival of said digital range signals in accordance with range-range techniques.
Claim 28
Dependent Claim
30 words
A positioning system as in claim 1 which is further adapted for use in a wireless telephone system operative in the microwave band from approximately 800 MHz to 2.5 GHz.
Claim 29
Dependent Claim
15 words
A positioning system as in claim 1 wherein said supplemental receiver comprises a wireless telephone.
Claim 30
Dependent Claim
17 words
A positioning system as in claim 1 wherein said supplemental receiver is a Personal Digital Assistant (PDA).
Claim 31
Dependent Claim
207 words
A positioning system for use in a wireless telephone system that includes a cell site transceiver that transmits and receives voice signals and control signals to and from a mobile telephone unit over one or more respective voice and primary control channels in order to provide wireless telephone service within a cell site coverage area, the positioning system comprising: a plurality of range transceivers at known fixed locations, each of which include a time reference base for transmitting an approximately synchronized digital range signal having a signal energy over one or more secondary control channels; at least one primary receiver at a known location relative to the locations of said range transceivers, which (a) receives the digital range signals, (b) determines a deviation representing the amount that each digital range signal deviates from system synchronization, and (c) sends corresponding error signals to said plurality of range transceivers over said secondary control channels so as to more closely bring said digital range signals into synchronization; and a mobile receiver at an unknown location which (a) receives said synchronized digital range signals over said secondary control channels, and (b) determines coordinate values defining its position based on the time difference of arrival of the received synchronized digital range signals.
Claim 32
Dependent Claim
207 words
A positioning system for use in a wireless telephone system that includes a cell site transceiver that transmits and receives voice signals and control signals to and from a mobile telephone unit over one or more respective voice and primary control channels in order to provide wireless telephone service within a cell site coverage area, the positioning system comprising: a plurality of range transceivers at known fixed locations, each of which include a time reference base for transmitting an approximately synchronized digital range signal having a signal energy over one or more secondary control channels; at least one primary receiver at a known location relative to the locations of said range transceivers, which (a) receives the digital range signals, (b) determines a deviation representing the amount that each digital range signal deviates from system synchronization, and (c) sends corresponding error signals to said plurality of range transceivers over said secondary control channels so as to more closely bring said digital range signals into synchronization; and a mobile receiver at an unknown location which (a) receives said synchronized digital range signals over said secondary control channels, and (b) determines coordinate values defining its position based on the time difference of arrival of the received synchronized digital range signals.
Claim 33
Dependent Claim
75 words
A positioning system as in claim 30 wherein said mobile receiver is further adapted to (a) compare said determined coordinate values to a stored set of coordinates corresponding to a predetermined zone of operation, (b) determine the position of the mobile receiver relative to the predetermined zone, and (c) transmit an electrical signal indicating whether said mobile unit is in or out of said zone over said primary control channel for receipt by said transceiver.
Claim 34
Dependent Claim
26 words
A positioning system as in claim 31 wherein said mobile receiver further comprises display means for displaying whether said mobile receiver is within said predetermined zone.
Claim 35
Dependent Claim
17 words
A positioning system as in claim 32 wherein said display means comprises a Light Emitting Diode (LED).
Claim 36
Dependent Claim
88 words
A positioning system as in claim 30 wherein said at least one primary receiver further comprises: a time detection device which detects and decodes said digital range signals; a precision time reference generated locally or received from a central source, said precision time reference having a selected accuracy sufficient for desired system tolerances; and a controller in electrical communication with said time detection device and said precision time reference which compares said decoded digital range signals with said reference signal to determine the deviation from the system synchronization.
Claim 37
Dependent Claim
32 words
A positioning system as in claim 30 wherein the plurality of said plurality of range transceivers are adapted to transmit said digital range signals sequentially in time using a time slotted protocol.
Claim 38
Dependent Claim
32 words
A positioning system as in claim 31 wherein the plurality of said plurality of range transceivers transmit said digital range signals simultaneously, each digital range signal having a unique code phase offset.
Claim 39
Dependent Claim
32 words
A positioning system as in claim 36 wherein said mobile receiver is adapted to compare said received digital range signals having known code phase offsets with a predetermined list of valid offsets.
Claim 40
Dependent Claim
39 words
A positioning system as in claim 30 wherein said mobile receiver ranks said digital range signals based on a weighted combination of the signal energy of said digital range signal and the location of said plurality of range transceivers.
Claim 41
Dependent Claim
31 words
A positioning system as in claim 36 wherein the plurality of range transceivers are further adapted to transmit said digital range signals on the same frequency so as to conserve bandwidth.
Claim 42
Dependent Claim
37 words
A positioning system as in claim 39 wherein said mobile receiver receives said digital range signals over an interval of time sufficient to overcome a degradation in signal to interference ratio on signals from distant range transceivers.
Claim 43
Dependent Claim
45 words
A positioning system as in claim 39 wherein said mobile receiver receives said digital range signals having code phase offsets selected to provide low autocorrelation sufficient to overcome a degradation in signal to interference ratio on said digital range signals received from distant range transceivers.
Claim 44
Dependent Claim
35 words
A positioning system as in claim 39 wherein said mobile receiver has a dynamic range sufficient to overcome a degradation in signal to interference ratio on said digital range signals received from distant range transceivers.
Claim 45
Dependent Claim
21 words
A positioning system as in claim 39 wherein said mobile receiver receives said digital range signals during a gated scanning period.
Claim 46
Dependent Claim
18 words
A positioning system as in claim 43 wherein said gated scanning period includes a narrow rotating null beam.
Claim 47
Dependent Claim
18 words
A positioning system as in claim 43 wherein said gated scanning period includes a narrow rotating fan beam.
Claim 48
Dependent Claim
37 words
A positioning system as in claim 39 wherein said plurality of range transceivers are each adapted to transmit a time stamp within said digital range signal, said time stamp adjusted by said range transceiver to simulate synchronization.
Claim 49
Dependent Claim
35 words
A positioning system as in claim 46 wherein said adjustments to said time stamps correspond to the last determined synchronization error of the corresponding digital range signals received by said at least one primary receiver.
Claim 50
Dependent Claim
44 words
A positioning system as in claim 30 wherein said plurality of range transceivers are further adapted to receive said error signals and correspondingly adjust the output of the next transmitted digital range signal so as to drive the detected synchronization error to approximately zero.
Claim 51
Dependent Claim
39 words
A positioning system as in claim 30 wherein said plurality of range transceivers are each adapted to transmit multiple pulse sequences, said pulse sequences including an error portion corresponding to the approximate synchronization error of each digital range signal.
Claim 52
Dependent Claim
43 words
A positioning system as in claim 49 wherein the error portions of said pulse sequences generated by said plurality of range transceivers correspond to the last determined synchronization errors of the corresponding digital range signals received by said at least one primary receiver.
Claim 53
Independent Claim
135 words
A method for determining the position of a mobile unit with respect to the positions of a plurality of range transceivers that are positioned at known fixed locations, wherein each transceiver transmits an approximately synchronized digital range signal, comprising: at a known location relative to the locations of said range transceivers, receiving the digital range signals by at least one primary receiver, determining a deviation representing the amount that each digital range signal deviates from system synchronization, and sending corresponding error signals to said primary range transceivers so as to more closely bring said digital range signals into synchronization; at a mobile unit's location, receiving said synchronized digital range signals; and computing, based on the time difference of arrival of the received synchronized digital range signals, coordinate values defining the position of said mobile unit.
Claim 54
Independent Claim
135 words
A method for determining the position of a mobile unit with respect to the positions of a plurality of range transceivers that are positioned at known fixed locations, wherein each transceiver transmits an approximately synchronized digital range signal, comprising: at a known location relative to the locations of said range transceivers, receiving the digital range signals by at least one primary receiver, determining a deviation representing the amount that each digital range signal deviates from system synchronization, and sending corresponding error signals to said primary range transceivers so as to more closely bring said digital range signals into synchronization; at a mobile unit's location, receiving said synchronized digital range signals; and computing, based on the time difference of arrival of the received synchronized digital range signals, coordinate values defining the position of said mobile unit.
Claim 55
Dependent Claim
49 words
The method of claim 51 wherein the step of determining the deviation from the system synchronization comprises: detecting and decoding said digital range signals; generating or receiving a reference signal having a selected accuracy sufficient for system tolerances; and comparing said decoded digital range signals with said reference signal.
Claim 56
Dependent Claim
53 words
The method of claim 51 wherein the digital range signal includes a time stamp and the method further comprising adjusting the time stamp of the next transmitted digital range signal of each of said plurality of range transceivers in accordance with said determined deviation from the system synchronization so as to simulate synchronization.
Claim 57
Dependent Claim
53 words
The method of claim 53 further comprising the step of adjusting the time stamp of the next range signal generated by each of said plurality of range transceivers in accordance with the last determined deviation from the system synchronization of the corresponding digital range signals received by said at least one primary receiver.
Claim 58
Dependent Claim
46 words
The method of claim 53 further comprising adjusting the output of the next transmitted digital range signal of each of said plurality of range transceivers in accordance with said determined deviation from the system synchronization so as to drive said corresponding error signals to approximately zero.
Claim 59
Dependent Claim
36 words
The method of claim 51 wherein said plurality of range transceivers are each adapted to transmit multiple pulse sequences, said pulse sequences including an error portion corresponding to the approximate synchronization error of each range signals.
Claim 60
Dependent Claim
54 words
The method of claim 56 further comprising the step of adjusting the error portion of the next digital range signal generated by each of said plurality of range transceivers in accordance with the last determined deviation from the system synchronization of the corresponding digital range signals received by said at least one primary receiver.
Claim 61
Dependent Claim
32 words
A positioning system as in claim 9 wherein the plurality of said range transceivers are further adapted to transmit said digital range signals on the same frequency so as to conserve bandwidth.
Claim 62
Dependent Claim
30 words
A positioning system as in claim 1 wherein said computation means is adapted to determine the time difference of arrival of said digital range signals in accordance with trilateration techniques.
Claim 63
Dependent Claim
32 words
A positioning system as in claim 35 wherein the plurality of said range transceivers are further adapted to transmit said digital range signals on the same frequency so as to conserve bandwidth.
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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) | 2000-02-04 | 2000-08-05 | 2001-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-02-04 | 2004-08-05 | 2005-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-02-04 | 2008-08-05 | 2009-02-04 | $7700.00 | Window Closed / Lapsed |