Patent US5874914A successfully refreshed from Google Patents.
US5874914A
Expired / Lapsed
US
⏱️ 0.0 years remaining
GPS receiver utilizing a communication link
Assignee: SnapTrack Inc
•
Filing: 1996-03-08
•
Granted: 1999-02-23
•
Expires: 2016-03-08
Abstract
Abstract A GPS receiver in one embodiment includes an antenna which receives GPS signals at an RF frequency from in view satellites; a downconverter coupled to the antenna for reducing the RF frequency of the received GPS signals to an intermediate frequency (IF); a digitizer coupled to the downconverter and sampling the IF GPS signals at a predetermined rate to produce sampled IF GPS signals; a memory coupled to the digitizer storing the sampled IF GPS signals (a snapshot of GPS signals); and a digital signal processor (DSP) coupled to the memory and operating under stored instructions thereby performing Fast Fourier Transform (FFT) operations on the sampled IF GPS signals to provide pseudorange information. These operations typically also include preprocessing and post processing of the GPS signals. After a snapshot of data is taken, the receiver front end is powered down. The GPS receiver in one embodiment also includes other power management features and includes, in another embodiment the capability to correct for errors in its local oscillator which is used to sample the GPS signals. The calculation speed of pseudoranges, and sensitivity of operation, is enhanced by the transmission of the Doppler frequency shifts of in view satellites to the receiver from an external source, such as a basestation in one embodiment of the invention.
Inventors
- 👤 Norman F. Krasner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:04
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/04; H; H04; H04B; H04B1/00; H04B1/38; H04B1/3805; G01S19/00; G01S19/01; G01S19/03; G01S19/05; G01S19/09; G01S19/13; G01S19/24; G01S19/25; G01S19/254; G01S19/258; G01S19/34; G01S19/35; G01S19/37; H01; H01Q; H01Q1/00; H01Q1/27; H01Q1/273; H01Q21/00; H01Q21/28; H03; H03J; H03J7/00; H03J7/02; H03J7/04; H03J7/06; H04B1/0003; H04B1/0007; H04B1/06; H04B1/16; H04B1/26; H04B1/28; G01S19/10; G01S19/11; G01S2205/00; G01S2205/001; G01S2205/008; G06; G06F; G06F2221/00; G06F2221/21; G06F2221/2111; H03D; H03D7/00; H03D7/16; H03D7/161; H03D7/163; H03J2200/00; H03J2200/11; H04B2001/3894
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
65 words
In a method for determining the position of a remote unit, a process comprising: receiving, at said remote unit from a transmission cell in a cellular communication system, a Doppler information of a satellite in view of said remote unit; and computing, in said remote unit, a position information for said satellite by using said Doppler information without receiving and without using satellite ephemeris information.
Claim 2
Dependent Claim
65 words
In a method for determining the position of a remote unit, a process comprising: receiving, at said remote unit from a transmission cell in a cellular communication system, a Doppler information of a satellite in view of said remote unit; and computing, in said remote unit, a position information for said satellite by using said Doppler information without receiving and without using satellite ephemeris information.
Claim 3
Dependent Claim
22 words
A process as in claim 1, further comprising: transmitting said Doppler information of said satellite from a basestation to said remote unit.
Claim 4
Dependent Claim
19 words
A process as in claim 2 wherein said Doppler information is obtained from a GPS receiver at said basestation.
Claim 5
Dependent Claim
26 words
A process as in claim 2 wherein said position information comprises pseudoranges to a plurality of satellites in view of said remote unit, including said satellite.
Claim 6
Dependent Claim
35 words
A process as in claim 4 further comprising: transmitting said pseudoranges from said remote unit to said basestation, and wherein said basestation computes a latitude and longitude which indicates the position of said remote unit.
Claim 7
Dependent Claim
26 words
A process as in claim 1 wherein a processing unit uses said Doppler information to compensate for a Doppler shift of GPS signals from said satellite.
Claim 8
Dependent Claim
21 words
A method as in claim 1 wherein said remote unit does not use satellite ephemeris information to determine said position information.
Claim 9
Dependent Claim
21 words
A method as in claim 1 wherein said remote unit does not receive satellite ephemeris information to determine said Doppler Information.
Claim 10
Dependent Claim
24 words
A method as in claim 1 wherein said remote unit does not demodulate a signal containing satellite ephemeris information to determine said Doppler information.
Claim 11
Dependent Claim
96 words
A mobile unit which uses data representative of GPS signals to provide the position of said mobile unit, said mobile unit comprising; a receiver in said mobile unit, said receiver operable for coupling through a cellular communications link in a transmission cell to receive a Doppler information of a satellite in view of said mobile unit; a processing unit in said mobile unit, said processing unit coupled to said receiver to receive said Doppler information and compute a position information for said satellite by using said Doppler information without receiving and without using satellite ephemeris information.
Claim 12
Dependent Claim
96 words
A mobile unit which uses data representative of GPS signals to provide the position of said mobile unit, said mobile unit comprising; a receiver in said mobile unit, said receiver operable for coupling through a cellular communications link in a transmission cell to receive a Doppler information of a satellite in view of said mobile unit; a processing unit in said mobile unit, said processing unit coupled to said receiver to receive said Doppler information and compute a position information for said satellite by using said Doppler information without receiving and without using satellite ephemeris information.
Claim 13
Dependent Claim
27 words
A mobile unit as in claim 10 wherein said processing unit uses said Doppler information to compensate for a Doppler shift of GPS signals from said satellite.
Claim 14
Dependent Claim
17 words
A mobile unit as in claim 11 wherein said communication link comprises a radio frequency communication medium.
Claim 15
Dependent Claim
23 words
A mobile unit as in claim 11 further comprising; a transmitter coupled to said processing unit, said transmitter for transmitting said position information.
Claim 16
Dependent Claim
24 words
A mobile unit as in claim 13 wherein said position information comprises pseudorange to a plurality of satellites in view of said mobile unit.
Claim 17
Dependent Claim
36 words
A mobile unit as in claim 11 wherein said processing unit comprises a digital signal processing integrated circuit (DSP) and wherein said DSP processes said GPS signals and said Doppler information using a fast convolution algorithm.
Claim 18
Dependent Claim
23 words
A mobile unit as in claim 15 further comprising: a transmitter coupled to said processing unit, said transmitter for transmitting said position information.
Claim 19
Independent Claim
92 words
A method of using a basestation for providing a communications link to a mobile GPS unit, said method comprising: determining a Doppler information of a satellite in view of said mobile GPS unit, wherein said Doppler information is used by said mobile GPS unit to determine a position information for said satellite; transmitting from a transmission cell in a cellular communication system said Doppler information of said satellite in view to said mobile GPS unit wherein said mobile GPS unit determines said position information without receiving and without using satellite ephemeris information.
Claim 20
Independent Claim
92 words
A method of using a basestation for providing a communications link to a mobile GPS unit, said method comprising: determining a Doppler information of a satellite in view of said mobile GPS unit, wherein said Doppler information is used by said mobile GPS unit to determine a position information for said satellite; transmitting from a transmission cell in a cellular communication system said Doppler information of said satellite in view to said mobile GPS unit wherein said mobile GPS unit determines said position information without receiving and without using satellite ephemeris information.
Claim 21
Dependent Claim
23 words
A method as in claim 17, wherein said Doppler information represents the Doppler shift of GPS signals from said satellite to said basestation.
Claim 22
Dependent Claim
26 words
A method as in claim 18 wherein said Doppler information approximately represents the Doppler shift of GPS signals from said satellite to said mobile GPS unit.
Claim 23
Dependent Claim
37 words
A method as in claim 17 wherein said Doppler information is obtained from a GPS receiver at said basestation and wherein said Doppler information represents the Doppler shift of GPS signals from said satellite to said basestation.
Claim 24
Dependent Claim
24 words
A method as in claim 20 wherein said Doppler information approximately represents the Doppler shift of GPS signals from said satellite mobile GPS unit.
Claim 25
Dependent Claim
43 words
A method as in claim 21 further comprising: receiving a position information from said mobile GPS unit, said position information being received at said basestation such that said basestation obtains a latitude and longitude which indicates the position of said mobile GPS unit.
Claim 26
Dependent Claim
39 words
A method as in claim 22 wherein said position information comprises pseudoranges to a plurality of satellites in view of said mobile GPS unit, including said satellite, and wherein said basestation computes said latitude and longitude from said pseudoranges.
Claim 27
Dependent Claim
15 words
A method as in claim 22 wherein said position information comprises said latitude and longitude.
Claim 28
Dependent Claim
27 words
A method as in claim 17 wherein said basestation does not transmit a satellite data message from which can be extracted a position information for a satellite.
Claim 29
Dependent Claim
80 words
A basestation for providing a cellular communication link to a mobile GPS unit, said basestation comprising: a source of a Doppler information of a satellite in view of said mobile GPS unit; a transmitter coupled to said source of said Doppler information, said transmitter for transmitting through said cellular communications link in a transmission cell said Doppler information to said mobile GPS unit wherein said mobile GPS unit determines a position information without receiving and without using satellite ephemeris information.
Claim 30
Dependent Claim
80 words
A basestation for providing a cellular communication link to a mobile GPS unit, said basestation comprising: a source of a Doppler information of a satellite in view of said mobile GPS unit; a transmitter coupled to said source of said Doppler information, said transmitter for transmitting through said cellular communications link in a transmission cell said Doppler information to said mobile GPS unit wherein said mobile GPS unit determines a position information without receiving and without using satellite ephemeris information.
Claim 31
Dependent Claim
32 words
A basestation as in claim 26 wherein said source of said Doppler information is a storage unit coupled to said basestation, said storage unit storing precalculated approximate Doppler information for said satellite.
Claim 32
Dependent Claim
26 words
A basestation as in claim 26 further comprising: a receiver for receiving a position information from said mobile GPS unit; a processor coupled to said receiver.
Claim 33
Dependent Claim
23 words
A basestation as in claim 26, wherein said Doppler information represents the Doppler shift of GPS signals from said satellite to said basestation.
Claim 34
Dependent Claim
26 words
A basestation as in claim 29, wherein said Doppler information approximately represents the Doppler shift of GPS signals from said satellite to said mobile GPS unit.
Claim 35
Dependent Claim
41 words
A basestation as in claim 26, wherein said Doppler information is obtained from said source which comprises a GPS receiver at said basestation and wherein said Doppler information represents the Doppler shift of GPS signals from said satellite to said basestation.
Claim 36
Dependent Claim
26 words
A basestation as in claim 31 wherein said Doppler information approximately represents the Doppler shift of GPS signals from said satellite to said mobile GPS unit.
Claim 37
Dependent Claim
33 words
A basestation as in claim 28, wherein said position information is received at said basestation such that said basestation obtains a latitude and longitude which indicates the position of said mobile GPS unit.
Claim 38
Dependent Claim
42 words
A basestation as in claim 33, wherein said position information comprises pseudoranges to a plurality of satellites in view of said mobile GPS unit, including said satellite, and wherein said processor of said basestation computes said latitude and longitude from said pseudorange.
Claim 39
Dependent Claim
22 words
A basestation as in claim 29 wherein said basestation and said mobile GPS unit are within approximately 150 kilometers of each other.
Claim 40
Independent Claim
119 words
A method for determining the position of a remote unit, comprising the steps of: transmitting through a transmission cell in a cellular communication system GPS satellite information, including Doppler information, to a remote unit from a basestation via a cellular data link; receiving at said remote unit said satellite information and GPS signals from in view satellites; computing, in the remote unit, pseudoranges to said in view satellites said pseudoranges computed using said Doppler information wherein said remote unit determines said pseudoranges without receiving and without using satellite ephemeris information; transmitting said pseudoranges to said basestation from said remote unit via said cellular data link; and computing, at said basestation, the position of said remote unit, using said pseudoranges.
Claim 41
Independent Claim
119 words
A method for determining the position of a remote unit, comprising the steps of: transmitting through a transmission cell in a cellular communication system GPS satellite information, including Doppler information, to a remote unit from a basestation via a cellular data link; receiving at said remote unit said satellite information and GPS signals from in view satellites; computing, in the remote unit, pseudoranges to said in view satellites said pseudoranges computed using said Doppler information wherein said remote unit determines said pseudoranges without receiving and without using satellite ephemeris information; transmitting said pseudoranges to said basestation from said remote unit via said cellular data link; and computing, at said basestation, the position of said remote unit, using said pseudoranges.
References Cited (Backward Citations)
US4445118A
Cited
US4601005A
Cited
US4797677A
Cited
US4701934A
Cited
US4785463A
Cited
US4910752A
Cited
US4959656A
Cited
US4998111A
Cited
EP0444738A2
Cited
US5416797A
Cited
EP0508405A1
Cited
US5225842A
Cited
US5202829A
Cited
US5271034A
Cited
US5379224A
Cited
US5280744A
Cited
US5323322A
Cited
US5223844B1
Cited
US5223844A
Cited
US5430759A
Cited
US5379047A
Cited
US5311194A
Cited
EP0601293A2
Cited
US5365450A
Cited
WO1994014081A1
Cited
US5523761A
Cited
US5323163A
Cited
US5317323A
Cited
US5379320A
Cited
US5334987A
Cited
US5420592A
Cited
US5633799A
Cited
US5389934A
Cited
US5554993A
Cited
US5483549A
Cited
US5512902A
Cited
DE4424412A1
Cited
US5592173A
Cited
US5626630A
Cited
US5650770A
Cited
US5594453A
Cited
WO1996015636A1
Cited
US5574469A
Cited
US5600329A
Cited
WO1997014049A2
Cited
GB2308033A
Cited
WO1997040398A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-02-22 | 2002-08-24 | 2003-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-22 | 2006-08-24 | 2007-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-22 | 2010-08-24 | 2011-02-23 | $7700.00 | Window Closed / Lapsed |