Indoor location using a packet synchronized receiver array

• US 9,485,745 B2
• Filed: 03/14/2014
• Issued: 11/01/2016
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Iposi, Inc.
• Original Assignee: Iposi, Inc.
• Inventors: Kurby, Chris, Lee, Richard M.
• Primary Examiner(s): Zewdu, Meless
• Application Number:
  US14/213,206
• Publication Number:
  US 20140370912A1
• Time in Patent Office: 963 Days
• US Class Current: 1/1
• CPC Class Codes: G01S 5/02216 Timing or synchronisation of the receivers
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence
• CPC Class Codes: G01S 5/08 Position of single direction-finder fixed by determining direction of a plurality of spaced sources of known location
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G01S 5/145 Using a supplementary range measurement, e.g. based on pseudo-range measurements
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Location of one or more devices in a monitored environment based at least in part on data communications between a device and a communication array disposed relative to the monitored environment. The communication array may include a plurality of nodes, at least two of which may be in operative communication with a mobile device. The plurality of nodes may be synchronized to a common time base with communications over a packet-switched communication network (e.g., employing IP communications or the like). In turn, communications between nodes of known location and a device may be used to determine ranging values at least in part based on characteristics (e.g., time of flight) of the communication. As such, a location may be determined by, for example, multilateration of a plurality of ranging values.

Claims

1. A system for determining a location of a mobile device in a monitored indoor environment, the system comprising:

a plurality of communication nodes distributed within the monitored indoor environment that define a communication array, wherein each of the plurality of communication nodes in the communication array is in operative communication with at least one mobile device for a data communication between the communication array and the mobile device, and wherein the plurality of communication nodes are disposed in known locations in the monitored indoor environment relative to a descriptor regarding the indoor environment;

a central hub in operative communication with the communication array by way of an asynchronous packet switched communication network, the central hub providing a synchronization communication to the communication array over the asynchronous packet switched communication network for synchronization of each of the plurality of communication nodes of the communication array to a common time base based on characteristics derived from the synchronization communication over the asynchronous packet switched commination network; and

a location determination module that is operative to determine the location of the mobile device within the monitored indoor environment relative to the communication array using at least the common time base and the data communication including, characteristic derived from the data communication comprising at least one of a time of arrival or a time difference of arrival, wherein the location of the mobile device is resolved in relation to the descriptor regarding the indoor environment.

2. The system of claim 1, wherein the data communication comprises an identifier corresponding to a source from which the data communication is sent.

3. The system of claim 2, wherein the data communication comprises a downlink communication and the source comprises a communication node.

4. The system of claim 2, wherein the data communication comprises an uplink communication and the source comprises the mobile device.

5. The system of claim 2, wherein the location determination module is operative to calculate a plurality of ranging values, wherein each ranging value of the plurality of ranging values corresponds to a measured distance between the mobile device and a respective communication node of the plurality of communication nodes, wherein each said ranging value of the plurality of ranging values is at least partially based on a measured time of flight of the data communication between a communication node of the plurality of communication nodes and the mobile device.

6. The system of claim 5, wherein the location determination module is operative to calculate a position of the mobile device relative to the communication array based on the plurality of ranging values relative to the known locations of the plurality of communication nodes in the communication array.

7. The system of claim 6, wherein the location determination module is at a location remote from the mobile device.

8. The system of claim 7, wherein the central hub comprises the location determination module.

9. The system of claim 6, wherein the location determination module is remote from the central hub.

10. The system of claim 6, wherein the mobile device comprises the location determination module.

11. The system of claim 10, wherein the mobile device is operative to communicate the position of the mobile device to the central hub.

12. The system of claim 6, wherein the location determination module is disposed at the central hub, and wherein each communication array is operative to time stamp the receipt of an uplink communication relative to the common time base and communicate the time stamp and the identifier to the central hub.

13. The system of claim 12, wherein the location determination module at the central hub is operative to determine a pseudorange between the mobile device and each said communication node of the communication array at least partially based on the time stamp relative to the common time base and location information for the respective said communication node of the communication array.

14. The system of claim 1, wherein the communication array comprises at least a first communication node of a first local area network (LAN) and at least a second communication node of a second LAN, wherein the first LAN is different than the second LAN.

15. The system of claim 14, wherein the central hub is in communication with the first communication node and the second communication node by way of a wide area network.

16. The system of claim 1, wherein the data communication comprises network communication data independent of any specific location determination information.

17. The system of claim 16, wherein the data communication comprises a reference signal.

18. The system of claim 17, wherein the reference signal comprises a sounding reference signal (SRS).

19. The system of claim 17, wherein the location determination module is operable to analyze the reference signal to discriminate valid signals corresponding to the data communication from invalid signals not corresponding to the data communication.

20. The system of claim 1, wherein the plurality of communication nodes are physically distributed throughout the monitored indoor environment, and wherein the monitored indoor environment corresponds to an area of overlapping communicability of the communication nodes.

21. The system of claim 1, further comprising:

a GNSS receiver operative to provide a location reference for the system.

22. The system of claim 21, wherein the GNSS receiver provides a GNSS time reference to the central hub.

23. The system of claim 22, wherein the common time base comprises the GNSS time reference.

24. The system of claim 1, wherein the descriptor comprises at least one of a map, floor plan, or georeference data.

25. A method for determining a location of a mobile device in a monitored indoor environment, the method comprising:

synchronizing a plurality of communication nodes to a central time base maintained at a central hub based on characteristics derived from communication of a synchronization communication between the plurality of communication nodes and the central hub over an asynchronous packet switched communication network, wherein the plurality of communication nodes are distributed in known locations within the monitored indoor environment relative to a descriptor of the monitored indoor environment and collectively define a communication array;

communicating a data communication between the communication array and the mobile device;

measuring a characteristic of the data communication comprising at least one of a time of arrival or a time difference of arrival; and

determining the location of the mobile device within the monitored indoor environment in relation to the descriptor of the monitored indoor environment using at least the common time base and the characteristic of the data communication.

26. The method of claim 25, wherein the determining comprises calculating a plurality of ranging values corresponding to distances between respective ones of the plurality of communication nodes and the mobile device.

27. The method of claim 26, wherein the determining comprises multilateration using the plurality of ranging values.

28. The method of claim 25, wherein the data communication comprises a downlink communication, and wherein the communicating comprises sending the downlink communication from the plurality of communication nodes to the mobile device.

29. The method of claim 25, wherein the data communication comprises an uplink communication, and wherein the communicating comprises sending the uplink communication from the mobile device to the plurality of communication nodes.

30. The method of claim 25, further comprising:

analyzing a plurality of received signals to determine if the received signals are valid.

31. The method of claim 30, wherein the analyzing comprises measuring an angle of arrival of the plurality of received signals.

32. The method of claim 31, wherein the analyzing comprises measuring a reference signal of the data communication corresponding to the received signal.

33. The method of claim 25, wherein the data communication comprises a data payload independent of any location function of the signal.