Claims
- 1. A method for locating a position of a mobile unit in a wireless communication network, said method comprising:
receiving a first RF fingerprint from said mobile unit, wherein said first RF fingerprint is indicative of a portion of the RF spectrum at said mobile unit at a first time; generating a first probability distribution for said position of said mobile unit based on said first fingerprint; receiving a second RF fingerprint from said mobile unit, wherein said second RF fingerprint is indicative of said portion of the RF spectrum at said mobile unit at a second time that is after said first time; and generating a second probability distribution for said position of said mobile unit based on a combination of said first probability distribution and said second fingerprint.
- 2. The method of claim 1 further comprising generating a filtered estimate of said position of said mobile unit at said second time based on said second probability distribution.
- 3. The method of claim 1 further comprising generating a smoothed estimate of said position of said mobile unit said first time based on said second probability distribution.
- 4. The method of claim 1 further comprising modifying said first probability distribution based on at least one possible motion of said mobile unit between said first time and said second time.
- 5. The method of claim 1 further comprising generating an estimate of said position of said mobile unit at said first time based on said second probability distribution and the expected location of said mobile unit.
- 6. The method of claim 1 further comprising generating an estimate of said position of said mobile unit at said first time based on said second probability distribution and the most probable location of said mobile unit.
- 7. A method comprising:
receiving a first RF fingerprint that is indicative of the signal attenuation between a mobile unit and at least one base station at a first time; generating a first probability distribution for a location of said mobile unit based on said first RF fingerprint; receiving a second RF fingerprint that is indicative of the signal attenuation between said mobile unit and at least one base station at a second time that is after said first time; and generating a second probability distribution for a location of said mobile unit based on a combination of said first probability distribution and said second fingerprint.
- 8. The method of claim 7 further comprising generating a filtered estimate of said position of said mobile unit at said second time based on said second probability distribution.
- 9. The method of claim 7 further comprising generating a smoothed estimate of said position of said mobile unit said first time based on said second probability distribution.
- 10. The method of claim 7 further comprising modifying said first probability distribution based on at least one possible motion of said mobile unit between said first time and said second time.
- 11. The method of claim 7 further comprising generating an estimate of said position of said mobile unit at said first time based on said second probability distribution and the expected location of said mobile unit.
- 12. The method of claim 7 further comprising generating an estimate of said position of said mobile unit at said first time based on said second probability distribution and the most probable location of said mobile unit.
- 13. A method comprising:
receiving a first RF fingerprint and a second RF fingerprint for a mobile unit, wherein said first RF fingerprint is taken at a first time, and wherein said second RF fingerprint is taken at a second time; estimating the location of said mobile unit at said second time based on said first RF fingerprint and said second RF fingerprint.
- 14. The method of claim 13 further comprising estimating the location of said mobile unit at said first time based on said first RF fingerprint.
- 15. The method of claim 13 wherein said first RF fingerprint is indicative of the signal attenuation between said mobile unit and at least one base station.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 10/128,128, filed 22 Apr. 2002 (now pending), which is continuation of U.S. patent application Ser. No. 09/532,418, filed 22 Mar. 2000 (now U.S. Pat. No. 6,393,294), which is a continuation-in-part of U.S. patent application Ser. No. 09/158,296, filed 22 Sep. 1998 (now U.S. Pat. No. 6,269,246). All of these applications are incorporated by reference.
Continuations (2)
|
Number |
Date |
Country |
Parent |
10128128 |
Apr 2002 |
US |
Child |
10910511 |
Aug 2004 |
US |
Parent |
09532418 |
Mar 2000 |
US |
Child |
10128128 |
Apr 2002 |
US |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09158296 |
Sep 1998 |
US |
Child |
09532418 |
Mar 2000 |
US |