SYSTEM AND METHOD OF UMTS UE LOCATION USING UPLINK DEDICATED PHYSICAL CONTROL CHANNEL AND DOWNLINK SYNCHRONIZATION CHANNEL

• US 20100087204A1
• Filed: 10/06/2008
• Published: 04/08/2010
• Est. Priority Date: 10/06/2008
• Status: Active Grant

• Current Assignee: Bison Patent Licensing, LLC
• Original Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Inventors: HANNAN, Ariful, CARLSON, John, ISLAM, Tariqul, Al-Mufti, Khalid
• Granted Patent: US 8,073,463 B2
• Time in Patent Office: Days
• US Class Current: 455/456.100
• CPC Class Codes: G01S 5/0215 Interference
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A system and method for estimating a location of a wireless device in a wireless communication system having a plurality of nodes and a plurality of location measurement units (“LMUs”). A set of signal samples from a first wireless device and a second wireless device may be collected by one or more LMUs in a search window. A first time of arrival (“TOA”) is determined, and a second search window is estimated as a function of the first TOA. A second TOA may be determined within the second search window at a second node or one of the LMUs from the set of signal samples. A range estimate of the wireless device may then be determined, and an estimated location of the wireless device may be determined as a function of the first uplink TOA, the second uplink TOA, or the range estimate and second TOA.

Claims

1. A method for estimating a location of a wireless device in a wireless communication system having a plurality of nodes and a plurality of location measurement units (“

LMU”

), the method comprising the steps of;

(a) collecting a plurality of signal samples from a first wireless device and a second wireless device by one or more LMUs in a first search window;

(b) determining a first time of arrival (“

TOA”

) from the plural signal samples;

(c) determining a second search window as a function of the first TOA;

(d) determining a second TOA from the plural signal samples in the second search window;

(e) determining a range estimate of the first wireless device; and

(f) determining an estimated location of the first wireless device as a function of the first TOA, the second TOA, or the range estimate and second TOA.

2. The method of claim 1 wherein the plural signal samples include signal samples representing both uplink and downlink spectrums.

3. The method of claim 1 wherein first wireless device is a user equipment.

4. The method of claim 1 wherein the second wireless device is a Node B.

5. The method of claim 1 wherein the second TOA is an uplink signal TOA.

6. The method of claim 1 further comprising the step of providing a request to a geolocation control server to locate the wireless device in the communication system.

7. The method of claim 6 wherein the request includes tipping information.

8. The method of claim 7 wherein the tipping information is provided by the communication system.

9. The method of claim 7 wherein the tipping information is extracted from messages exchanged between the wireless device and a node.

10. The method of claim 1 wherein determining a first TOA further comprises:

(i) recreating an uplink pilot signal in at least one LMU; and

(ii) correlating the recreated uplink pilot signal against the plural signal samples.

11. The method of claim 1 wherein at least one LMU is not co-located with a respective node.

12. The method of claim 1 wherein the step of determining a range estimate further comprises comparing uplink and downlink frame markers from the plural signal samples.

13. The method of claim 1 wherein the estimated location of the wireless device is determined as a function of a value selected from the group consisting of sector geometry and sector axis.

14. The method of claim 1 wherein the second search window is determined as a function of downlink dedicated physical channel frame timing or fractional dedicated channel frame timing.

15. The method of claim 1 wherein the second search window is determined as a function of round trip time and Rx-Tx time difference type 2 parameters.

16. The method of claim 1 wherein the nodes are selected from the group consisting of:

base stations, base station sectors, and combinations thereof.

17. The method of claim 1 wherein the communication system is selected from the group consisting of:

Universal Mobile Telecommunications System (“

UMTS”

) network, Worldwide Interoperability for Microwave Access (“

WiMax”

) network, Global System for Mobile Communications (“

GSM”

) network, Orthogonal Frequency Division Multiple Access (“

OFDMA”

) network, WiFi network, and Code Division Multiple Access (“

CDMA”

) network.

18. The method of claim 17 wherein the system operates under a standard selected from the group consisting of:

IS-95, Evolution-Data Optimized (“

EVDO”

), CDMA2000, Long Term Evolution (“

LTE”

) and 1 times Radio Transmission Technology (“

1×

RTT”

).

19. A method for estimating a location of a wireless device in a wireless communication system having a plurality of nodes and a plurality of location measurement units (“

LMU”

), the method comprising the steps of;

(a) collecting a set of signal samples from a first wireless device and a second wireless device by one or more LMUs in a search window determined as a function of a first uplink time of arrival (“

TOA”

) from a first node;

(b) determining a second uplink TOA at a second node or the one or more LMUs from the set of signal samples;

(c) determining a range estimate of the wireless device; and

(d) determining an estimated location of the wireless device as a function of the first uplink TOA, the second uplink TOA, or the range estimate and second TOA.

20. The method of claim 19 wherein the first node is a serving node and the second node is a neighboring node.

21. The method of claim 19 wherein the first node is a neighboring node and the second node is selected from the group consisting of serving node and neighboring node.

22. The method of claim 19 wherein the search window is determined as a function of sector geometry.

23. The method of claim 19 wherein the nodes are selected from the group consisting of:

base stations, base station sectors, and combinations thereof.

24. The method of claim 19 wherein at least one LMU is not co-located with a respective node.

25. A method for estimating a location of a wireless device in a communication system having a plurality of nodes and a plurality of location measurement units (“

LMU”

), comprising the steps of;

(a) collecting signal samples from the wireless device by one or more LMUs;

(b) detecting a time of arrival (“

TOA”

) from the signal samples, the detecting including;

(i) segmenting the collected signal samples to a predetermined length,

(ii) determining an ambiguity function or correlation for each segment, and

(iii) adding the ambiguity functions or correlations to detect a TOA; and

(c) determining an estimated location of the wireless device as a function of the TOA,

wherein a demeaned peak to standard deviation ratio is applied to the added ambiguity functions or correlations.

26. The method of claim 25 wherein the ambiguity functions or correlations are coherently or non-coherently added.

27. The method of claim 25 wherein detecting a TOA further comprises:

(iv) selecting a TOA as a function of a detection threshold or quality.

28. A method for estimating a location of a wireless device in a communication system having a plurality of nodes and a plurality of location measurement units (“

LMU”

), comprising the steps of;

(a) collecting signal samples from the wireless device by one or more LMUs;

(b) detecting a time of arrival (“

TOA”

) from the signal samples, the detecting including;

(i) determining a mixing product of the collected signal samples,

(ii) decimating the mixing product,

(iii) segmenting the decimated product to predetermined lengths,

(iv) determining ambiguity functions for each segment, and

(v) adding the ambiguity functions to detect a TOA; and

(c) determining an estimated location of the wireless device as a function of the TOA,

wherein a demeaned peak to standard deviation ratio is applied to the added ambiguity functions.

29. The method of claim 28 wherein the ambiguity functions are coherently or non-coherently added.

30. The method of claim 28 wherein detecting a TOA further comprises:

(vi) selecting a TOA as a function of a detection threshold or quality.

31. In a communication system having a plurality of nodes and a plurality of location measurement units (“

LMU”

), a method for estimating a location of a wireless device, the method comprising collecting signal samples from the wireless device by one or more LMUs, detecting a time of arrival (“

TOA”

) from the signal samples, and determining an estimated location of the wireless device as a function of the TOA, the improvement wherein the TOA is detected without regard to noise and gain variation in the collected signal samples.

32. A method for estimating a location of a wireless device in a wireless communication system having a plurality of nodes and a plurality of location measurement units (“

LMU”

), the method comprising the steps of;

(a) collecting a set of signal samples from a first wireless device and a second wireless device by one or more LMUs in a search window determined as a function of a first uplink time of arrival (“

TOA”

) from a first node;

(b) detecting a second uplink TOA at a second node or LMU from the set of signal samples by a plurality of non-coherent additions of ambiguity functions;

(c) determining a range estimate of the wireless device; and

(d) determining an estimated location of the wireless device as a function of the first uplink TOA, the second uplink TOA, or the range estimate and second TOA.

33. The method of claim 32 wherein the step of detecting a second TOA further comprises:

(i) segmenting the collected signal samples to a predetermined length,

(ii) determining an ambiguity function or correlation for each segment, and

(iii) adding the ambiguity functions or correlations to detect the TOA,

wherein a demeaned peak to standard deviation ratio is applied to the added ambiguity functions or correlations.

34. The method of claim 33 wherein the ambiguity functions or correlations are coherently or non-coherently added.

35. The method of claim 33 further comprising iteratively repeating steps (i) through (iii) for different sized portions.

36. The method of claim 32 wherein the step of detecting a second TOA further comprises:

(i) determining a mixing product of the collected signal samples,

(ii) decimating the mixing product,

(iii) segmenting the decimated product to predetermined lengths,

(iv) determining ambiguity functions for each segment, and

(v) adding the ambiguity functions to detect the TOA,

wherein a demeaned peak to standard deviation ratio is applied to the added ambiguity functions.

37. The method of claim 36 wherein the ambiguity functions are coherently or non-coherently added.

38. The method of claim 36 further comprising iteratively repeating steps (i) through (v) for different sized portions.