Method and apparatus for evaluation of position location performance

• US 6,556,832 B1
• Filed: 02/04/2000
• Issued: 04/29/2003
• Est. Priority Date: 02/04/2000
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Soliman, Samir S.
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Tran, Congvan
• Application Number:
  US09/497,718
• Time in Patent Office: 1,180 Days
• Field of Search: 455/456, 455/422, 455/403, 455/414, 455/418, 455/421, 455/423, 455/424, 455/448, 455/186.1, 455/454, 455/440, 342/457, 342/357.06, 342/357-9-3
• US Class Current: 455/456.5
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services

Abstract

Several different approaches may be taken to adding mobile unit position location capability to a system for wireless communications. These approaches may include terrestrial techniques as well as satellite-based techniques. An apparatus is disclosed whereby different such approaches may be evaluated and compared in the context of a particular existing or proposed system for wireless communications.

Claims

1. An apparatus comprising:

a structured collection of information relating at least in part to a target region;

at least one processing unit;

wherein the at least one processing unit processes at least a portion of the structured collection of information and produces further information;

wherein the further information relates at least in part to a predicted position location performance of at least one system for locating a position of a wireless unit within the target region; and

wherein the further information includes an evaluation of the predicted position location performance based upon performance criteria, the performance criteria including at least one among a percentage of the target region wherein positions may be located to an acceptable degree of accuracy, an area of uncertainty associated with a located position, a minimum time required to locate a position, a number of requests for position location that may be serviced, a rate at which position location determinations may be updated, and a cost associated with position location.

2. An apparatus comprising:

a structured collection of information relating at least in part to a target region;

at least one processing unit;

wherein the at least one processing unit processes at least a portion of the structured collection of information and produces further information;

wherein the further information relates at least in part to a predicted position location performance of at least one system for locating a position of a wireless unit within the target region;

wherein the structured collection of information comprises at least one among topological information relating to the target region, demographic information relating to the target region, and information relating to distribution of a population within the target region; and

wherein the structured collection of information includes a demand vector, each element of the demand vector corresponding to at least one of the plurality of bins.

3. The apparatus according to claim 2, wherein the demand vector is based at least in part on at least one among a custom demand map, a land-use map, a population density map, and demographic information.

4. An apparatus comprising:

a structured collection of information relating at least in part to a target region;

at least one processing unit;

wherein the at least one processing unit processes at least a portion of the structured collection of information and produces further information;

wherein the further information relates at least in part to a predicted position location performance of at least one system for locating a position of a wireless unit within the target region;

wherein the structured collection of information comprises at least one among topological information relating to the target region, demographic information relating to the target region, and information relating to distribution of a population within the target region; and

wherein the structured collection of information includes a representation of the target region, the representation of the target region comprising a plurality of bins, each bin corresponding to one among an area element and a volume element of the target region.

5. The apparatus according to claim 4, wherein the predicted position location performance includes values corresponding to each of at least a portion of the plurality of bins, each of the values relating to a location of a position of a wireless unit within the corresponding bin.

6. The apparatus according to claim 4, wherein the structured collection of information includes a propagation loss matrix, each element of the propagation loss matrix corresponding to one or more of the plurality of bins.

7. The apparatus according to claim 6, wherein the values of each of the elements of at least a portion of the propagation loss matrix are based on at least one among a path loss model and a diffraction loss model.

8. The apparatus according to claim 7, wherein the path loss model includes at least one among a free-space loss model, a short-term model, and a long-term model.

9. The apparatus according to claim 6, wherein the at least one system for determining a position of a wireless unit within the target region includes a terrestrial locating system, said terrestrial locating system comprising a plurality of base stations.

10. The apparatus according to claim 9, wherein the terrestrial locating system includes at least one among an overlay infrastructure-based system and an integrated infrastructure-based system.

11. The apparatus according to claim 9, wherein the terrestrial locating system determines the position of the wireless unit at least on the basis of a time difference of arrival of a signal from the wireless unit.

12. The apparatus according to claim 9, wherein at least a portion of the predicted position location performance is obtained at least in part using a forward link analysis.

13. The apparatus according to claim 9, wherein at least a portion of the predicted position location performance is obtained at least in part using a reverse link analysis.

14. The apparatus according to claim 13, wherein the reverse link analysis is based at least in part on an effective radiated power of the wireless unit.

15. The apparatus according to claim 13, wherein the reverse link analysis is based at least in part on a maximum tolerable path loss between the specified one of the plurality of bins and at least one of the plurality of base station units.

16. The apparatus according to claim 9, wherein the predicted position location performance includes an analysis of errors relating to position location, the errors relating to position location including at least one among errors due to noise, errors due to multipath interference, and errors due to quantization.

17. The apparatus according to claim 16, wherein the errors relating to position location include at least one among uncertainty in the position of at least one of the plurality of base station units and uncertainty in the transmit time of a signal from the wireless unit.

18. The apparatus according to claim 16, wherein the analysis of errors relating to position location includes the calculation of at least one ambiguity factor, the at least one ambiguity factor including at least one among dilution of precision (DOP), geometric DOP, position DOP, horizontal DOP, and time DOP.

19. The apparatus according to claim 6, wherein the at least one system for determining a position of a wireless unit within the target region comprises a satellite-based locating system.

20. The apparatus according to claim 19, wherein the satellite-based locating system includes one among a stand-alone mobile-unit-based system, a network-assisted system, and a network-based system.

21. The apparatus according to claim 19, wherein the satellite-based locating system receives signals from satellites of at least one among the NAVSTAR and the GLONASS Global Positioning Satellite systems.

22. The apparatus according to claim 19, wherein the predicted position location performance is based at least in part upon a calculation of the positions of a plurality of satellites in a Global Positioning Satellite system at specified times.

23. The apparatus according to claim 19, wherein the predicted position location performance is based at least in part on the visibility of a plurality of satellites in a Global Positioning Satellite system at a specified bin.

24. The apparatus according to claim 19, wherein the predicted position location performance includes an analysis of errors relating to position location, wherein the errors relating to position location include at least one among errors due to noise, errors due to multipath interference, and errors due to quantization.

25. The apparatus according to claim 24, wherein the errors relating to position location include at least one among errors associated with atmospheric conditions and errors associated with selective availability.

26. The apparatus according to claim 24, wherein the analysis of errors relating to position location includes the calculation of at least one ambiguity factor, the at least one ambiguity factor including at least one among dilution of precision (DOP), geometric DOP, position DOP, vertical DOP, horizontal DOP, time DOP, and relative DOP.

27. The apparatus according to claim 6, wherein at least one system for determining a position of a wireless unit located within the target region comprises a hybrid locating system,

wherein the hybrid locating system includes at least a portion of a terrestrial locating system and at least a portion of a satellite-based locating system.

28. An apparatus comprising:

a topological database;

a propagation loss matrix; and

at least one processing unit,

wherein the topological database relates at least in part to a target region, and

wherein each among at least a portion of the elements of the propagation loss matrix represents a path loss between positions in the target region, and

wherein the at least one processing unit performs at least one among a forward link analysis and a reverse link analysis, at least one link analysis being based at least in part on information from the topological database and information from the propagation loss matrix, and

wherein the at least one processing unit outputs information relating to a predicted position location performance of a wireless unit locating system with respect to the target region.

29. The apparatus of claim 28, wherein the processing unit calculates the positions of a plurality of global positioning satellites at a plurality of times, and

wherein the processing unit performs a satellite visibility analysis.

30. The apparatus of claim 28, wherein the processing unit outputs information relating to a predicted position location performance of a hybrid locating system.

31. The apparatus of claim 28, the apparatus further comprising a demand vector, at least one link analysis being based at least in part on information from the demand vector.