Cellular telephone using pseudolites for determining location

• US 6,564,064 B1
• Filed: 12/01/1999
• Issued: 05/13/2003
• Est. Priority Date: 12/01/1999
• Status: Expired due to Term

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Janky, James M., Ciganer, Ann
• Primary Examiner(s): Hunter, Daniel
• Assistant Examiner(s): Nguyen, Thuan T.
• Application Number:
  US09/452,900
• Time in Patent Office: 1,259 Days
• Field of Search: 455/456, 455/457, 455/427, 455/12.1, 455/11.1, 342/357.02, 342/457, 342/418, 342/357.05, 701/214
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 19/256 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 19/37 Hardware or software details of the signal processing chain
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A cellular telephone having a global positioning system (GPS) receiver using a blended combination of GPS signals from GPS satellites and GPS pseudolites for determining a location. The cellular telephone includes a cellphone transceiver and a GPS receiver. The cellular transceiver receives wireless downlink cellphone signals from the cell site transceiver and transmits wireless uplink cellphone signals to the cell site transceiver. The cell site transceiver passes voice and data from the downlink and uplink cellphone signals within a local area into the worldwide network of telephone services. The GPS receiver receives satellite GPS signals from GPS satellites and pseudolite GPS signals from GPS pseudolites. The GPS pseudolites augment the GPS satellites for the local area by broadcasting pseudolite GPS signals having location-determination information with a format that is similar to the format in the satellite GPS signals. The GPS receiver uses either the satellite GPS signals, the pseudolite GPS signals, or a blended combination of the satellite and pseudolite GPS signals for determining its location. Then, the cellphone transceiver reports the location to the cell site transceiver in the uplink cellphone signal. The cell site transceiver transmits a downlink cellphone signal having acquisition aiding information optionally including GPS-based time; ephemeris orbital parameters for GPS satellites; and pseudorandom (PRN) codes, locations, and signal characteristics used by GPS pseudolites in the local vicinity. The GPS receiver in the cellular telephone uses the acquisition aiding information for speeding the time to the first location fix.

Claims

1. A cellular telephone, comprising:

a GPS digital signal processor for determining a time-of-arrival for a satellite GPS signal transmitted from a GPS satellite and a time-of-arrival for a pseudolite GPS signal transmitted from a GPS pseudolite, said pseudolite GPS signal transmitted in on/off bursts having pseudorandom intervals between said bursts; and

a memory coupled to the GPS digital signal processor, the memory including pseudolite characteristic data for a characteristic of said bursts and a navigation program having instructions for using said pseudolite characteristic data for acquisition of said pseudolite GPS signal and then using a blended combination of said time-of-arrival of said satellite GPS signal and said time-of-arrival for said pseudolite GPS signal for determining a cellphone location.

2. The cellular telephone of claim 1, wherein:

the memory further includes data for the location of said GPS pseudolite; and

said navigation program is further for using said GPS pseudolite location data for determining said cellphone location.

3. The cellular telephone of claim 1, further comprising:

a cellphone transceiver for receiving a downlink cellphone signal including acquisition aiding information including said burst characteristic, and for passing said burst characteristic to the GPS digital signal processor.

4. The cellular telephone of claim 1, wherein:

said on/off bursts have an average duty cycle in a range of one to ten percent.

5. The cellular telephone of claim 1, wherein:

said GPS pseudolite avoids collisions for said pseudolite GPS signal by listening for other GPS pseudolite signals before transmitting.

6. A cellular telephone, comprising:

a GPS digital signal processor for determining a time-of-arrival for a satellite GPS signal transmitted from a GPS satellite and a time-of-arrival for a pseudolite GPS signal transmitted from a GPS pseudolite;

a memory coupled to the GPS digital signal processor, the memory including a navigation program having instructions for using a blended combination of said time-of-arrival of said satellite GPS signal and said time-of-arrival for said pseudolite GPS signal for determining a cellphone location;

a cellphone transceiver for receiving a downlink cellphone signal including acquisition aiding information including a pseudorandom (PRN) code for said GPS pseudolite; and

the GPS digital signal processor is further for using said PRN code for determining said time-of-arrival of said pseudolite GPS signal.

7. The cellular telephone of claim 6, wherein:

the cellphone transceiver is further for transmitting an uplink cellphone signal including information for said cellphone location to a cell site transceiver.

8. The cellular telephone of claim 7, wherein:

said uplink cellphone signal further includes a telephone number; and

said cell site transceiver is for passing said cellphone location to a user at said telephone number.

9. The cellular telephone of claim 6, wherein:

the cellphone transceiver is further for receiving a downlink cellphone signal including acquisition aiding information including a location of said GPS pseudolite, and for using said GPS pseudolite location for determining said cellphone location.

10. The cellular telephone of claim 6, wherein:

said pseudolite GPS signal includes a pseudolite PRN code transmitted in on/off bursts; and

the GPS digital signal processor includes a pseudolite pseudorandom (PRN) code generator for providing a replica pseudolite PRN code, a burst code multiplier for multiplying said replica pseudolite PRN code with a representation of said pseudolite GPS signal for providing burst code products, and a burst correlator for accumulating said burst code products for determining said time-of-arrival of said pseudolite GPS signal.

11. A method for determining a location of a cellular telephone, comprising steps of:

determining a time-of-arrival for a satellite GPS signal transmitted from a GPS satellite;

determining a time-of-arrival for a pseudolite GPS signal transmitted from a GPS pseudolite in on/off bursts having pseudorandom intervals between said bursts;

storing a characteristic of said bursts in said cellular telephone; and

determining said location of said cellular telephone using said characteristic of said bursts for acquisition of said pseudolite GPS signal and then using a blended combination of said time-of-arrival of said satellite GPS signal and said time-of-arrival for said pseudolite GPS signal.

12. The method of claim 11, further comprising a step of:

storing data for a location of said GPS pseudolite; and

wherein;

the step of determining said location of said cellular telephone includes using said location data for said GPS pseudolite.

13. The method of claim 11, further comprising a step of:

receiving a downlink cellphone signal including acquisition aiding information including said burst characteristic.

14. The method of claim 11, wherein:

said on/off bursts have an average duty cycle in a range of one to ten percent.

15. The method of claim 11, wherein:

said GPS pseudolite avoids collisions for said pseudolite GPS signal by listening for other GPS pseudolite signals before transmitting.

16. A method for determining a location of a cellular telephone, comprising steps of:

determining a time-of-arrival for a satellite GPS signal transmitted from a GPS satellite;

determining a time-of-arrival for a pseudolite GPS signal transmitted from a GPS pseudolite in on/off bursts;

determining said location of said cellular telephone using a blended combination of said time-of-arrival of said satellite GPS signal and said time-of-arrival for said pseudolite GPS signal;

receiving a downlink cellphone signal including acquisition aiding information including a pseudorandom (PRN) code for said GPS pseudolite; and

wherein;

the step of determining said time-of-arrival of said pseudolite GPS signal includes using said PRN code.

17. The method of claim 16, further comprising a step of:

transmitting an uplink cellphone signal including said location of said cellular telephone to a cell site transceiver.

18. The method of claim 17, wherein:

said uplink cellphone signal further includes a telephone number; and

further including a step of;

passing said cellphone location from said cell site transceiver to a user at said telephone number.

19. The method of claim 16, further comprising a step of:

receiving a downlink cellphone signal including acquisition aiding information including location data for said GPS pseudolite.

20. The method of claim 16, wherein:

said pseudolite GPS signal includes a pseudolite PRN code transmitted in on/off bursts; and

the step of determining said time-of-arrival of said pseudolite GPS signal further includes steps of;

generating a replica pseudolite PRN code;

multiplying a representation of said pseudolite GPS signal with said replica pseudolite PRN code for providing burst code products;

accumulating said burst code products for providing a correlation signal; and

determining said time-of-arrival of said pseudolite GPS signal from said correlation signal.