Method and apparatus for determining time for GPS receivers

• US 6,433,734 B1
• Filed: 10/30/2000
• Issued: 08/13/2002
• Est. Priority Date: 03/08/1996
• Status: Expired due to Term

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Inventors: Krasner, Norman F.
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US09/702,960
• Time in Patent Office: 652 Days
• Field of Search: 342/357.09, 342/357.1, 455/456
• US Class Current: 342/357.64
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/06 employing an initial estimate of the location of the receiver as aiding data or in generating aiding data
• CPC Class Codes: G01S 19/07 providing data for correcting measured positioning data, e.g. DGPS [differential GPS] or ionosphere corrections
• CPC Class Codes: G01S 19/071 DGPS corrections
• CPC Class Codes: G01S 19/09 providing processing capability normally carried out by the receiver
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/235 Calibration of receiver components
• CPC Class Codes: G01S 19/252 Employing an initial estimate of location in generating assistance data
• CPC Class Codes: G01S 19/254 relating to Doppler shift of satellite signals
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 19/37 Hardware or software details of the signal processing chain
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/0045 Transmission from base station to mobile station G01S5/009 takes precedence
• CPC Class Codes: G01S 5/009 Transmission of differential positioning data to mobile
• CPC Class Codes: H03J 7/04 where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
• CPC Class Codes: H03J 7/047 : Automatic frequency control using an auxiliary signal, e.g. low frequency scanning of the locking range or superimposing a special signal on the input signal
• CPC Class Codes: H04B 1/00 : Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
• CPC Class Codes: H04B 1/0007 : wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
• CPC Class Codes: H04B 1/28 : the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04B 1/3805 : with built-in auxiliary receivers

Abstract

A method and apparatus of determining the time for a global positioning system receiver is disclosed. Timing signals derived from a communication system, such as cellular phone transmission signals, are received by a GPS receiver and decoded to provide accurate time information. The timing signals may be in the form of synchronized events marked by timing indicators, or as system time information. The timing signals in combination with satellite position signals received by the GPS receiver are used to determine the position of the GPS receiver.

Claims

1. A method for aiding the determination of a position of a mobile global positioning system (GPS) receiver which is coupled to a cellular communication receiver, said method comprising:

monitoring transmissions of a cellular communications signal from a cellular communication cell site by an entity not co-located with said mobile GPS receiver;

determining by said entity a time-of-day of at least a portion of said transmissions and determining a specific cell site associated with said portion; and

determining a position information of said mobile GPS receiver from said time-of-day and said specific cell site.

2. A method as in claim 1 wherein said transmissions are cellular telephone signals and wherein said time-of-day is determined using a GPS time.

3. A method as in claim 1 wherein said entity monitors framing information transmitted by said cellular communication cell site and wherein said time-of-day is associated with said framing information.

4. A method as in claim 3 wherein said cellular communications signal utilizes one of the GSM cellular communication type standard, a TDMA type standard or a CDMA type standard.

5. A method as in claim 1 wherein said entity contains a cellular telephone.

6. A method as in claim 2 further comprising:

transmitting said time-of-day to said mobile GPS receiver.

7. A method for aiding the determination of a position of a mobile global positioning system (GPS) receiver which is coupled to a cellular communication receiver, said method comprising:

monitoring transmissions of a cellular communications signal from a cellular communication cell site by an entity not co-located with said mobile GPS receiver;

determining by said entity a time-of-day of at least a portion of said transmissions and determining a specific cell site associated with said portion; and

transmitting a representation of said time-of-day to said mobile GPS receiver.

8. A method as in claim 7 wherein said transmissions are cellular telephone signals and wherein said time-of-day is determined using a GPS time.

9. A method as in claim 7 wherein said entity monitors framing information transmitted by said cellular communication cell site and wherein said time-of-day is associated with said framing information.

10. A method as in claim 9 wherein said cellular communications signal utilizes one of the GSM cellular communication type standard, a TDMA type standard or a CDMA type standard.

11. A method as in claim 7 wherein said entity contains a cellular telephone.

12. A system for aiding the determination of a position of a mobile global positioning system (GPS) receiver which is coupled to a cellular communication receiver, said system comprising:

a receiver coupled to an antenna, said receiver monitoring transmissions of a cellular communications signal from a cellular communication cell site by a first entity not co-located with said mobile GPS receiver;

a processor coupled to said receiver, said processor determining by said first entity a time-of-day of at least a portion of said transmissions and determining a specific cell site associated with said portion; and

a transmitter coupled to said processor, said transmitter transmitting a representation of said time-of-day to a second entity in order to determine a position of said mobile GPS receiver.

13. A system as in claim 12 wherein said transmissions are cellular telephone signals and wherein said time-of-day is determined using a GPS time.

14. A system as in claim 12 wherein said second entity is said mobile GPS receiver.