Multi-path mitigation in rangefinding and tracking objects using reduced attenuation RF technology

• US 8,305,215 B2
• Filed: 05/17/2011
• Issued: 11/06/2012
• Est. Priority Date: 12/15/2005
• Status: Active Grant

• Current Assignee: Qualcomm Technologies Incorporated (Qualcomm, Inc.)
• Original Assignee: InvisiTrack, Inc.
• Inventors: Markhovsky, Felix, Prevatt, Truman
• Primary Examiner(s): Bugg, George
• Assistant Examiner(s): Labbees, Edny
• Application Number:
  US13/109,904
• Publication Number:
  US 20110256882A1
• Time in Patent Office: 539 Days
• Field of Search: 3405721-5729, 340/539.13, 340/825.49, 340/568.1, 340/541, 340/573.1, 342/47, 342/204, 702/158, 235375-385, 235/425, 235/560, 455/403, 455/404.2, 455/440, 455/456.1, 455/457, 455/506
• US Class Current: 340/572.1
• CPC Class Codes: G01S 13/767 Responders; Transponders teaching or practice apparatus for gun-aiming or gun-laying using reflecting targets or active targets F41G3/26
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 2013/466 by Trilateration, i.e. two antennas or two sensors determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the antennas or sensors, the position data of the target is determined
• CPC Class Codes: G01S 2013/468 by Triangulation, i.e. two antennas or two sensors determine separately the bearing, direction or angle to a target, whereby with the knowledge of the baseline length, the position data of the target is determined
• CPC Class Codes: G01S 3/74 Multi-channel systems specially adapted for direction-finding, i.e. having a single antenna system capable of giving simultaneous indications of the directions of different signals systems in which the directions of different signals are determined sequentially and displayed simultaneously G01S3/04, G01S3/14
• CPC Class Codes: G01S 5/0205 Details
• CPC Class Codes: G01S 5/0218 Multipath in signal reception
• CPC Class Codes: G01S 5/0273 using multipath or indirect path propagation signals in position determination
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location

Abstract

A method and system for identification, tracking and locating in wireless communications and wireless networks. The method and system use reference and/or pilot signals that are present in wireless communications and wireless networks. The method and system can also use RTT, TOA and time-stamping measurements/techniques to determine one or more reference signals traveling time between the Base Station (eNB) or its functional equivalent and mobile device (UE) and or network device. The method and system includes multi-path mitigations processor and multi-path mitigations techniques and algorithms which improve the track-locate accuracy. The method and system allow achieving increased accuracy by using multi-path mitigations processor and multi-path mitigations techniques and algorithms. The techniques of Digital Signal Processing and Software-Defined Radio are used.

Claims

1. A system for tracking and locating wireless network devices, comprising:

a multipath mitigation processor configured to receive and process one or more signals of the wireless network devices and configured to perform ranging between the wireless network devices, wherein the multipath mitigation processor is configured to perform a high-resolution spectrum estimation analysis on the one or more signals to reduce spatial ambiguity in ranging between the wireless network devices, the high-resolution spectrum estimation analysis producing a plurality of artificial frequencies, estimating a model size for the plurality of artificial frequencies, and calculating a distance measurement based on a distribution of the plurality of artificial frequencies.

2. The system as recited in claim 1, wherein the multipath mitigation processor is configured to use one or more methods to reduce a multi-path interference error.

3. The system as recited in claim 1, wherein the multipath mitigation processor is configured to receive the one or more signals to compute a channel response to range one or more of the wireless network devices.

4. The system as recited in claim 1, wherein the multipath mitigation processor is configured to use a channel response computed by the wireless network devices for determining a ranging measurement.

5. The system as recited in claim 1, wherein the one or more signals are narrow bandwidth signals.

6. The system as recited in claim 1, wherein the one or more signals are wide bandwidth signals including different individual narrow bandwidth frequency components.

7. The system as recited in claim 1, wherein the multipath mitigation processor is configured to support a half-duplex, a full duplex or a simplex mode of operation.

8. The system as recited in claim 1, wherein the one or more signals are OFDM signals.

9. The system as recited in claim 1, wherein the multipath mitigation processor is configured to employ a noise reduction method.

10. The system as recited in claim 1, wherein the multipath mitigation processor is configured to reduce a remainder of a multipath interference error by applying a post-processing technique.

11. The system as recited in claim 1, wherein the multipath mitigation processor is configured to perform ranging utilizing a method from the group of methods comprising:

Time of Arrival (TOA);

Differential Time of Arrival (DTOA);

TOA and DTOA;

Time of Flight (TOF);

TOF and Angle of Arrival (AOA);

TOA and AOA;

Triangulation;

Trilateration;

Triangulation and Trilateration;

Virtual triangulation;

Reverse Virtual Triangulation;

Virtual triangulation and Reverse Virtual Triangulation;

Observed Time Difference of Arrival (OTDOA);

OTDOA and Downlink OTDOA (DL-OTDOA);

Cell ID;

Round Trip Time (RTT);

CELL ID and RTT;

Cell ID and AOA; and

Cell ID and AOA and RTT.

12. A method for tracking and locating wireless network devices, comprising the steps of:

receiving and processing one or more signals of the wireless network devices;

using a multipath mitigation processor to perform ranging between the wireless network devices based on the one or more signals; and

using the multipath mitigation process to perform a high-resolution spectrum estimation analysis on the one or more signals to reduce ranging measurement spatial ambiguity between the wireless network devices, including the steps of producing a plurality of artificial frequencies, estimating a model size for the plurality of artificial frequencies, and reducing the ranging measurement spatial ambiguity based on a distribution of the plurality of artificial frequencies.

13. The method as recited in claim 12, wherein a wireless network frame received from and transmitted to the wireless network devices includes the one or more signals.

14. The method as recited in claim 12, wherein the one or more signals is a wide bandwidth signal including different individual narrow bandwidth frequency components.

15. The method as recited in claim 14, further comprising the step of generating the wide bandwidth signal and a base-band wide bandwidth signal from the different individual narrow bandwidth frequency components.

16. The method as recited in claim 12, wherein the one or more signals are OFDM signals.

17. The method as recited in claim 12, wherein the one or more signals are one or more pilot signals, one or more sub-carrier signals or a combination of the one or more pilot signals and the one or more sub-carrier signals.

18. The method as recited in claim 12, further comprising the step of employing a noise reduction method.

19. The method as recited in claim 12, further comprising the step of reducing a remainder of a multipath interference error by applying a post-processing technique.

20. The method as recited in claim 12, further comprising the step of using one or more methods to reduce a multi-path interference error.

21. The method as recited in claim 12, wherein the step of using multipath mitigation processor further includes the step of utilizing a method from the group of methods comprising:

Time of Arrival (TOA);

Differential Time of Arrival (DTOA);

TOA and DTOA;

Time of Flight (TOF);

TOF and Angle of Arrival (AOA);

TOA and AOA;

Triangulation;

Trilateration;

Triangulation and Trilateration;

Virtual triangulation;

Reverse Virtual Triangulation;

Virtual triangulation and Reverse Virtual Triangulation;

Observed Time Difference of Arrival (OTDOA);

OTDOA and Downlink OTDOA (DL-OTDOA);

Cell ID;

Round Trip Time (RTT);

CELL ID and RTT;

Cell ID and AOA; and

Cell ID and AOA and RTT.

22. A system for tracking and locating wireless network devices, comprising:

a wireless receiver configured to interface to the wireless network devices to receive one or more signals from the wireless network devices; and

a multipath mitigation processor configured to receive and process the one or more signals and configured to perform an Angle of Arrival (AOA) ranging from one or more of the wireless network devices based on the one or more signals, the wireless receiver configured to interface to the multipath mitigation processor;

wherein the multipath mitigation processor is further configured to perform a high-resolution spectrum estimation analysis on the one or more signals to reduce spatial ambiguity in a distance measurement, the high-resolution spectrum estimation analysis producing a plurality of artificial frequencies, estimating a model size for the plurality of artificial frequencies, and calculating the distance measurement based on a distribution of the plurality of artificial frequencies.

24. The system as recited in claim 22, wherein the multipath mitigation processor is configured to use one or more methods to reduce a multi-path interference error.

23. The system as recited in 22, wherein the multipath mitigation processor is configured to perform ranging utilizing a method from the group of methods comprising:

Time of Arrival (TOA);

Differential Time of Arrival (DTOA);

TOA and DTOA;

Time of Flight (TOF);

TOF and Angle of Arrival (AOA);

TOA and AOA;

Triangulation;

Trilateration;

Triangulation and Trilateration;

Virtual triangulation;

Reverse Virtual Triangulation;

Virtual triangulation and Reverse Virtual Triangulation;

Observed Time Difference of Arrival (OTDOA);

OTDOA and Downlink OTDOA (DL-OTDOA);

Cell ID;

Round Trip Time (RTT);

CELL ID and RTT;

Cell ID and AOA; and

Cell ID and AOA and RTT.