Ranging system using active radio frequency (RF) nodes

• US 9,689,955 B2
• Filed: 06/08/2012
• Issued: 06/27/2017
• Est. Priority Date: 02/24/2011
• Status: Active Grant

• Current Assignee: Corvus Technologies Corp.
• Original Assignee: Corvus Technologies Corp.
• Inventors: Rosenbaum, Glen Var
• Primary Examiner(s): Jia, Xin
• Application Number:
  US13/492,587
• Publication Number:
  US 20160007315A1
• Time in Patent Office: 1,845 Days
• Field of Search: 455 6711
• CPC Class Codes: G01S 3/46 using antennas spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination

Abstract

A ranging system includes at least one beacon and a control module. The at least one beacon is configured to scan each segment in a plurality of segments of an arc with a narrow radio frequency (RF) beam and receive a response signal from an end user node in at least one segment. Each segment of the arc is scanned at a specified time interval. The control module is configured to communicate with the at least one beacon. The control module is further configured to calculate at least one of an angle-of-arrival (AOA) and a time-of-flight (TOF) of a response signal from the end user node to the beacon and generate an end user node location relative to a beacon location.

Claims

1. A ranging system, comprising:

at least one beacon configured to;

scan each segment in a plurality of segments of an arc with a narrow radio frequency (RF) beam, wherein each narrow RF beam is a phase modulated pulsed signal packet forming at least one pulsed interrogation at each segment; and

receive a pulsed response signal packet from an end user node in at least one segment that responds to the at least one pulsed interrogation from the beacon, wherein each segment of the arc is sequentially scanned at a specified time interval; and

a control module configured to;

communicate with the at least one beacon, wherein the control module is further configured to calculate at least one of an angle-of-arrival (AOA) and a time-of-flight (TOF) of the pulsed response signal transmitted from the end user node to the beacon; and

generate an end user node location of the end user node relative to a beacon location.

2. The ranging system of claim 1, further comprising:

the end user node configured to receive at least one of the narrow RF beams and transmit the pulsed response signal back to the beacon, wherein the pulsed response signal is a modulated version or original format of the pulsed interrogation.

3. The ranging system of claim 2, wherein the end user node further includes a transducer, a sensor, or a microcontroller to capture biometric information or node telemetry data, wherein the response signal includes at least one of biometric information of an end user and node telemetry data captured by the end user node.

4. The ranging system of claim 2, wherein the end user node has a linear antenna and the interrogation is circularly polarized.

5. The ranging system of claim 1, further comprising:

at least two beacons located at different positions from each other, wherein each beacon is configured to scan a different arc with a plurality of segments with a narrow RF beam and each beacon is in communication with the control module, wherein each narrow RF beam is a phase modulated pulsed signal forming at least one pulsed interrogation at each segment, and wherein the control module is configured to generate the end user node location relative to the beacon locations by triangulating the pulsed response signal from each beacon using the AOA or the TOF of each response signal.

6. The ranging system of claim 1, wherein the control module is configured to generate the end user node location relative to a single beacon location by using the AOA and the TOF of the response signal.

7. The ranging system of claim 1, wherein the control module is configured to calculate the AOA using a received signal strength indicator (RSSI).

8. The ranging system of claim 1, wherein the end user node location is a three-dimensional (3-D) location.

9. The ranging system of claim 1, wherein the beacon includes a phased array antenna configured to scan along two axes including horizontally and vertically with scanning angle ranging from +/−

60°

horizontal and +/−

45°

vertical.

10. The ranging system of claim 9, wherein the beacon comprises an electronic scanned array (ESA) antenna comprising an array of radiator elements associated with phase shifters for each radiator element.

11. The ranging system of claim 10, further comprising a monopole antenna configured to wirelessly communicate with one or both of the control module and the at least one beacon.

12. The ranging system of claim 1, wherein each segment of the arc is from 0.2°

to 20°

.

13. The ranging system of claim 1, wherein the ranging system uses a modified Institute of Electrical and Electronics Engineers (IEEE) 802.15.4 standard or modified Zigbee protocol for signal transmissions, wherein the modified IEEE 802.15.4 or modified Zigbee protocol reduces scanning time by reducing a number of messages or by reducing a dwell time in a handshaking protocol via messaging including received signal strength indicator (RSSI) information.

14. The ranging system of claim 1, wherein the control module includes at least one of a recording module for recording or tracking at least one of the end user node location, biometric information of an end user, and node telemetry data from the end user node over a time duration.

15. The ranging system of claim 1, wherein the control module includes a mapping module for overlaying a map of a beacon area using existing map data of the beacon area, wherein the beacon area is an area where the beacon is configured to communicate with end user nodes.

16. The ranging system of claim 1, wherein the beacon is configured to provide pulsed switching time interval of the interrogation pulse and the pulsed response.

17. A method for determining a location of an end user node relative to the at least one beacon, comprising:

sequentially scanning, at the beacon, each of a plurality of segments in an arc with a separate narrow radio frequency (RF) beam transmitted from the at least one beacon, wherein each narrow RF beam is a phase modulated pulsed signal packet forming at least one pulsed interrogation at each segment and the arc is in a direction of the end user node;

receiving at the beacon a pulsed response packet signal from the end user node based on a received narrow RF beam at the end user node;

determining at least one of an angle-of-arrival (AOA) and a time-of-flight (TOF) of the response signal; and

calculating an end user node location of the end user node relative to at least one beacon location using at least one of the AOA and TOF of the response signal.

18. The method of claim 17, wherein

scanning uses at least two beacons located at a different positions from each other, and each beacon scans a different arc with a plurality of segments with a narrow RF beam, wherein the narrow RF beam has at least a 30 decibel isotropic (dBi) bi-directional gain for high penetration and less than a 20 degree beam width for low scattering into and throughout a perimeter of interest, wherein the scanning is accomplished using an electronic scanned array (ESA) antenna to produce the phase modulated pulsed signal at each segment;

calculating the end user node location further comprises;

triangulating response signals from each beacon using the AOA or the TOF of each response signal to generate the end user node location relative to the beacon locations.

19. The method of claim 18, wherein calculating the end user node location further comprises selecting the end user node location based on the AOA of a greatest RSSI strength of the response signal or a shortest TOF of the response signal from a majority of beacons corresponding to the end user node location.

20. The method of claim 17, wherein

scanning uses one beacon, and

calculating the end user node location uses the AOA and the TOF of the response signal.

21. The method of claim 17, wherein determining at least one of the AOA and the TOF of the response signal further comprises:

selecting the segment of the arc with a greatest received signal strength indicator (RSSI) strength of a plurality of received response signals or a plurality of transmitted narrow RF beams as indicated by a RSSI of the received response signals measured at the beacon or a RSSI of the transmitted narrow RF beam measured at the end user node and fed back in the received response signals.

22. The method of claim 17, further comprising:

receiving, at the beacon from the end user node, end user node information selected from the group consisting of biometric information, half-duplex voice packets, direction and range of travel, telemetry information, and a received signal strength indicator (RSSI) of the transmitted and received narrow RF beam.

23. The method of claim 17, further comprising:

transmitting, from the beacon to the end user node, control module information selected from the group consisting of a half-duplex voice packet, inquiries, an internet protocol (IP) message, and combinations thereof.