US6204812B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods and apparatus to position a mobile receiver using downlink signals, part II
Assignee: CELL-LOC LOCATION TECHNOLOGIES Inc
•
Filing: 1998-10-09
•
Granted: 2001-03-20
•
Expires: 2018-10-09
Abstract
Abstract The invention consists of methods and apparatus to estimate the position and velocity of a Mobile Receiver (MR) using either the Time Of Arrival (TOA) of signals received by the MR, their Phase Of Arrival (POA), their Strength Of Arrival (SOA), their Frequency Of Arrival (FOA), or a combination thereof, with respect to a reference produced by a Reference Receiver (RR) of known location. In order to solve for the coordinates of the MR, the invention uses either hyperbolic multilateration based on Time Difference Of Arrival (TDOA), or linear multiangulation based on Phase Difference Of Arrival (PDOA), or both. In order to solve for the velocity of the MR, the patent uses FOA based on Frequency Difference Of Arrival (FDOA). An important contribution of this invention is the way the MR receives, processes and combines available signals for location purposes. Another important contribution of this invention is the way the RR receives, processes and combines available signals for reference purposes.
Inventors
- 👤 Michel Fattouche
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:27
CPC Classifications
H; H04; H04W; H04W64/00; G; G01; G01S; G01S5/00; G01S5/0009; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/185; H04B7/1853; H04B7/18539; G01S2205/00; G01S2205/001; G01S2205/008; G01S5/02; G01S5/08; G01S5/10; G01S5/12; G01S5/14
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
90 words
A system to estimate the location of a mobile receiver, the system comprising: an IF receiver for receiving a plurality of RF signals r i (t) transmitted by a plurality of base stations, the IF receiver being configured to generate an IF signal, the IF receiver including a local oscillator and an RF synthesizer for controlling the local oscillator; and an estimator for estimating the carrier offset due to Doppler, δf i , and due to local oscillator offset, Δf i of the plurality of RF signals r i (t).
Claim 2
Independent Claim
90 words
A system to estimate the location of a mobile receiver, the system comprising: an IF receiver for receiving a plurality of RF signals r i (t) transmitted by a plurality of base stations, the IF receiver being configured to generate an IF signal, the IF receiver including a local oscillator and an RF synthesizer for controlling the local oscillator; and an estimator for estimating the carrier offset due to Doppler, δf i , and due to local oscillator offset, Δf i of the plurality of RF signals r i (t).
Claim 3
Dependent Claim
16 words
The system of claim 1 further comprising a processor for performing a discrete Carrier Recovery Loop.
Claim 4
Dependent Claim
75 words
The system of claim 2 wherein the carrier recovery loop comprises a processor configured to repeat the following steps until a satisfactory level of performance is reached: process the IF signal to derive an adequate objective function, f obj ; if f obj is optimized to within a certain constraint, stop the loop, otherwise: search for a new frequency offset, adjust the local oscillator by the new frequency offset, and go back to step 1.
Claim 5
Dependent Claim
23 words
The system of claim 3 wherein the search for a new frequency offset in step 3 is performed using a gradient-type search algorithm.
Claim 6
Dependent Claim
31 words
The system of claim 3 wherein adjusting the local oscillator by the new frequency offset is performed either using a Direct Digital Synthesizer or a Digital Down-Converter or a combination thereof.
Claim 7
Dependent Claim
44 words
The system of claim 3 further comprising a Host and the Host is connected to receive the estimated carrier offset last found and process the estimated carrier offset to aid in estimating the speed v of the mobile receiver and its Direction Of Travel.
Claim 8
Dependent Claim
50 words
The system of claim 2 wherein the processor performs the function of a carrier recovery loop by performing a digital notch filtering operation centered at a desired IF frequency f 2 , and whose power of response is an optimized objective function, f obj , derived from the IF signal.
Claim 9
Dependent Claim
45 words
The system of claim 7 in which the digital notch filtering operation consists of: a first digital Band Pass Filter centered at the f 2 +frequency of desired Tone; and a second digital Band Pass Filter centered at the f 2 −frequency of desired Tone.
Claim 10
Dependent Claim
54 words
The system of claim 2 wherein the processor is configured to perform the function of a carrier recovery loop by performing a digital Band Pass filtering operation centered at a desired IF frequency f 2 , and whose power of response is an optimized objective function, f obj , derived from the IF signal.
Claim 11
Dependent Claim
23 words
The system of claim 9 wherein the desired IF frequency f 2 is equal to zero and the digital BPF is a LPF.
Claim 12
Dependent Claim
16 words
The system of claim 9 wherein both Band Pass filters are implemented using digital Biquadratic filters.
Claim 13
Dependent Claim
16 words
The system of claim 1 in which the IF receiver is part of the mobile receiver.
Claim 14
Dependent Claim
20 words
The system of claim 12 in which the estimator comprises a processor configured to perform a discrete Carrier Recovery Loop.
Claim 15
Dependent Claim
75 words
The system of claim 13 wherein the carrier recovery loop comprises a processor configured to perform the following steps until a satisfactory level of performance is reached: process the IF signal to derive an adequate objective function, f obj ; if f obj is optimized to within a certain constraint, stop the loop, otherwise: search for a new frequency offset, adjust the local oscillator by the new frequency offset, and go back to step 1.
Claim 16
Dependent Claim
23 words
The system of claim 14 wherein the search for a new frequency offset in step 3 is performed using a gradient-type search algorithm.
Claim 17
Dependent Claim
29 words
The system of claim 14 wherein adjusting the local oscillator by the new frequency offset is performed either using a DDS or a Digital Down-Converter or a combination thereof.
Claim 18
Dependent Claim
42 words
The system of claim 14 further comprising a Host and the Host is connected to receive the estimated carrier offset last found and process the estimated carrier offset to estimate the speed v of the mobile receiver and its Direction Of Travel.
Claim 19
Dependent Claim
30 words
The system of claim 17 wherein the speed of the cellular telephone and its direction of traveling is estimated as a function of the difference between the estimated carrier offsets.
Claim 20
Dependent Claim
53 words
The system of claim 13 wherein the processor is configured to perform the function of a carrier recovery loop by performing a digital notch filtering operation centered at a desired IF frequency f 2 , and whose power of response is an optimized objective function, f obj , derived from the IF signal.
Claim 21
Dependent Claim
45 words
The system of claim 17 in which the digital notch filtering operation consists of: a first digital Band Pass Filter centered at the f 2 +frequency of desired Tone; and a second digital Band Pass Filter centered at the f 2 −frequency of desired Tone.
Claim 22
Dependent Claim
54 words
The system of claim 13 wherein the processor is configured to perform the function of a carrier recovery loop by performing a digital Band Pass filtering operation centered at a desired IF frequency f 2 , and whose power of response is an optimized objective function, f obj , derived from the IF signal.
Claim 23
Dependent Claim
23 words
The system of claim 21 wherein the desired IF frequency f 2 is equal to zero and the digital BPF is a LPF.
Claim 24
Dependent Claim
16 words
The system of claim 21 wherein both Band Pass filters are implemented using digital Biquadratic filters.
Claim 25
Dependent Claim
21 words
The system of claim 1 in which the RF synthesizer is responsive to the carrier offset to control the local oscillator.
Claim 26
Dependent Claim
29 words
The system of claim 24 in which the RF synthesizer is configured to adjust the local oscillator to remove the carrier offset from the output of the local oscillator.
Claim 27
Dependent Claim
24 words
The system of claim 1 further comprising a processor operably connected to the IF receiver for generating a location estimate for the mobile receiver.
Claim 28
Independent Claim
61 words
A method of estimating the location of a mobile receiver, the method comprising the steps of: estimating the carrier offset due to Doppler, δf i , and due to local oscillator offset, Δf i of a plurality of signals transmitted by a plurality of base stations and received by a reference receiver having a local oscillator; and processing the carrier offset.
Claim 29
Independent Claim
61 words
A method of estimating the location of a mobile receiver, the method comprising the steps of: estimating the carrier offset due to Doppler, δf i , and due to local oscillator offset, Δf i of a plurality of signals transmitted by a plurality of base stations and received by a reference receiver having a local oscillator; and processing the carrier offset.
Claim 30
Independent Claim
56 words
A method of estimating the location of a mobile receiver, the method comprising the steps of: estimating the carrier offset due to Doppler, δf i , and due to local oscillator offset, Δf of a plurality of signals transmitted by a plurality of base stations and received by the mobile receiver; and processing the carrier offset.
Claim 31
Independent Claim
56 words
A method of estimating the location of a mobile receiver, the method comprising the steps of: estimating the carrier offset due to Doppler, δf i , and due to local oscillator offset, Δf of a plurality of signals transmitted by a plurality of base stations and received by the mobile receiver; and processing the carrier offset.
References Cited (Backward Citations)
US3384891A
Cited
US3646580A
Cited
US3680121A
Cited
US3609568A
Cited
US3824595A
Cited
US4433335A
Cited
US4177466A
Cited
US4310722A
Cited
US4297701A
Cited
US4437075A
Cited
US4651156A
Cited
US4870422A
Cited
US4639733A
Cited
US4596988A
Cited
US4638321A
Cited
US4651157A
Cited
US4791572A
Cited
US4818998A
Cited
US4908629A
Cited
US4728959A
Cited
US4742357A
Cited
US5023809A
Cited
US4916455A
Cited
US4891650A
Cited
US5055851A
Cited
US5003317A
Cited
US4975710A
Cited
US4926161A
Cited
US5101501A
Cited
US5126748A
Cited
US5095500A
Cited
US5023900A
Cited
US5008679A
Cited
US5153902A
Cited
US5128623A
Cited
US5218618A
Cited
US5148452A
Cited
US5208756A
Cited
US5173710A
Cited
WO1993006685A1
Cited
US5293645A
Cited
US5600706A
Cited
US5467065A
Cited
US5317323A
Cited
US5327144A
Cited
US5666662A
Cited
US5412388A
Cited
US5404376A
Cited
US5570305A
Cited
CA2108103A1
Cited
US5646632A
Cited
US5541608A
Cited
US5508708A
Cited
US5764188A
Cited
US5736964A
Cited
US5724660A
Cited
US5764687A
Cited
US5717403A
Cited
US5731787A
Cited
US5663734A
Cited
US5781156A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-19 | 2004-09-18 | 2005-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-19 | 2008-09-18 | 2009-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-19 | 2012-09-18 | 2013-03-20 | $7700.00 | Window Closed / Lapsed |