Patents by Inventor Sampath Rangarajan

Sampath Rangarajan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20210231792
    Abstract: A product locating system is provided. The system includes at least one Radio Frequency (RF) backscatter transmitter configured to emit a main carrier RF signal that forms an excitation signal. The system further includes a passive RF backscatter tag associated with a product and configured to generate an Ultra-Wideband (UWB) signal from the excitation signal. The system also includes at least one RF backscatter receiver configured to simultaneously receive both the excitation signal from the at least one RF backscatter transmitter and the UWB signal from the passive RF backscatter tag, and compute the time-difference-of-arrival (TDoA) therebetween. TDoA information from multiple RF backscatter receivers, including the at least one RF backscatter receiver, is aggregated to compute the location of the product to which the passive RF backscatter tag is attached.
    Type: Application
    Filed: January 25, 2021
    Publication date: July 29, 2021
    Inventors: Karthikeyan Sundaresan, Sampath Rangarajan
  • Patent number: 11055502
    Abstract: Systems and methods for sequential detection-based classifications of radio-frequency identification (RFID) tags in three-dimensional space are provided. The methods include modeling a response from RFID tags as a probabilistic macro-channel and interrogating an RFID tag by transmitting a series of packets. Each packet is a transmit symbol and a first series of packet is a transmitted codeword. The method includes receiving, from the RFID tag, a second series of packets that is a received codeword in response to the transmitted codeword and finding a jointly typical transmit and receive codeword across all classes of macro-channels. The method also includes declaring a class of the RFID tag based on a largest likelihood between the transmitted codeword and the received codeword.
    Type: Grant
    Filed: July 22, 2019
    Date of Patent: July 6, 2021
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Patent number: 11054843
    Abstract: A computer-implemented method, system, and computer program product are provided for positioning an unmanned autonomous vehicle (UAV) in a long term evolution radio access network. The method includes acquiring, by a processor-device, a position of the UAV with a global position system. The method also includes determining, by the processor-device, physical distances from the UAV to each of a plurality of user equipment (UE) responsive to a time-of-flight from the UAV to each of the plurality of UE. The method additionally includes generating, by the processor-device, radio environment maps for each of the plurality of UE with signal-to-noise ratios (SNR) from each of the plurality of UEs to the UAV. The method further includes selecting, by the processor-device, a determined position for the UAV as a position with a minimum SNR in the REMs. The method also includes commanding the UAV to move to the determined position.
    Type: Grant
    Filed: March 1, 2019
    Date of Patent: July 6, 2021
    Inventors: Karthikeyan Sundaresan, Eugene Chai, Sampath Rangarajan, Mohammad Khojastepour, Ayon Chakraborty
  • Patent number: 11048890
    Abstract: Systems and methods for implementing a radio frequency identifier (RFID) system are provided. The methods include transmitting a radio frequency (RF) signal, by an RFID interrogator with multiple antennas. The methods include receiving a superimposed received signal. The superimposed received signal includes replies from a first RFID tag and a second RFID tag that are overlapping in time. The methods also include separating the replies from the first RFID tag and second RFID tag though spatial processing of the superimposed received signal.
    Type: Grant
    Filed: September 10, 2019
    Date of Patent: June 29, 2021
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20210088323
    Abstract: Aspects of the present disclosure describe systems, methods and structures that perform linear-grammetry and calibration by simultaneous multilateration using only edge distance estimates via two-way ranging.
    Type: Application
    Filed: September 18, 2020
    Publication date: March 25, 2021
    Applicant: NEC LABORATORIES AMERICA, INC
    Inventors: Mohammad KHOJASTEPOUR, Sampath RANGARAJAN
  • Patent number: 10943419
    Abstract: A walk-though gate (WTG) is presented. The WTG includes a WTG structure including a first wall and a second wall, the first and second walls defining a walk though pass way between an entrance and exit, at least one sensor located at the entrance and the exit of a cavity defined by the walk though pass way, at least one first antenna facing toward an inside region of the WTG structure, at least one second antenna facing away from the inside region of the WTG structure, an RFID reader connected to the at least one first and second antennas, and a judgement module to judge if an RFID tag is located inside or outside the walk though gate structure.
    Type: Grant
    Filed: November 20, 2019
    Date of Patent: March 9, 2021
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20210067899
    Abstract: Systems and methods for localizing and tracking mobile objects are provided. The method includes determining an initial location of a node based on multi-lateration from an unmanned aerial vehicle and determining a velocity vector associated with the node based on multi-lateration. The method also includes detecting when the node turns. An adaptive aperture is applied to address a non-uniform velocity of the node based on the turn and the velocity vector.
    Type: Application
    Filed: September 12, 2019
    Publication date: March 4, 2021
    Inventors: Karthikeyan Sundaresan, Ayon Chakraborty, Sampath Rangarajan, Ashutosh Dhekne
  • Patent number: 10936927
    Abstract: A product tagging system is provided. The product tagging system includes at least one RF backscatter transmitter configured to emit (i) a main carrier RF signal, and (ii) Radio Frequency (RF) signals on two frequencies whose summation forms a twin carrier RF signal. The product tagging system further includes a passive RF backscatter tag associated with a product and configured to reflect and frequency shift the main carrier RF signal to a different frequency using the twin carrier RF signal. The product tagging system also includes at least one RF backscatter receiver configured to read the product on the different frequency by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the main carrier RF signal by the passive RF backscatter tag.
    Type: Grant
    Filed: January 15, 2020
    Date of Patent: March 2, 2021
    Inventors: Karthikeyan Sundaresan, Eugene Chai, Sampath Rangarajan, Mohammad Rostami
  • Patent number: 10930102
    Abstract: A method includes constructing a WTG structure including a first wall and a second wall, the first and second walls defining a walk though pass way between an entrance and an exit, positioning at least one sensor at the entrance and the exit of a cavity defined by the walk though pass way, positioning at least one first antenna facing toward an inside region of the WTG structure, positioning at least one second antenna facing away from the inside region of the WTG structure, connecting an RFID reader to the at least one first and second antennas, and, judging, via a judgement module, if an RFID tag is located inside or outside the walk though gate structure.
    Type: Grant
    Filed: November 20, 2019
    Date of Patent: February 23, 2021
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Patent number: 10852413
    Abstract: A product tagging system is provided. The product tagging system includes at least one RF backscatter transmitter configured to emit a Radio Frequency (RF) signal on a frequency. The product tagging system further includes a passive RF backscatter tag associated with a product and configured to reflect and frequency shift the RF signal to a different frequency. The product tagging system also includes at least one RF backscatter receiver configured to read the product on the different frequency by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the RF signal by the passive RF backscatter tag.
    Type: Grant
    Filed: April 11, 2019
    Date of Patent: December 1, 2020
    Inventors: Karthikeyan Sundaresan, Eugene Chai, Sampath Rangarajan
  • Patent number: 10852414
    Abstract: An in-home inventory and location system is provided. At least one RF backscatter transmitter, hosted on a device, is configured to emit a RF signal on a frequency. A set of passive RF backscatter tags, each associated with a respective one of a plurality of products in a given area, is configured to reflect and frequency shift the RF signal to a different frequency. At least one RF backscatter receiver, hosted on another device, is configured to read the products on the different frequency by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the RF signal by the passive RF backscatter tag. At least one of the device hosting the at least one RF backscatter transmitter and the other device hosting the at least one RF backscatter receiver is configured to maintain an inventory and location of the products in the given area.
    Type: Grant
    Filed: September 25, 2019
    Date of Patent: December 1, 2020
    Inventors: Karthikeyan Sundaresan, Eugene Chai, Sampath Rangarajan
  • Patent number: 10852416
    Abstract: An in-store interaction and location system is provided. At least one RF backscatter transmitter, hosted on a device, is configured to emit a RF signal on a frequency. A set of passive RF backscatter tags, each associated with a respective one of a plurality of products in a given store area, is configured to reflect and frequency shift the RF signal to a different frequency. At least one RF backscatter receiver, hosted on another device, is configured to read the plurality of products on the different frequency by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the RF signal by the passive RF backscatter tag. At least one of the device and the other device is configured to maintain an inventory and a location of the plurality of products in the given store area and provide the inventory and location to a user device.
    Type: Grant
    Filed: September 25, 2019
    Date of Patent: December 1, 2020
    Inventors: Karthikeyan Sundaresan, Eugene Chai, Sampath Rangarajan
  • Patent number: 10852415
    Abstract: A navigation assistance system is provided. At least one RF backscatter transmitter, hosted on a device, is configured to emit a RF signal on a frequency. A set of passive RF backscatter tags, each associated with a respective one of a plurality of navigation markers in a given venue, is configured to reflect the RF signal and frequency shift the RF signal to a different frequency. At least one RF backscatter receiver is configured to read the navigation markers on the different frequency by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the RF signal by the passive RF backscatter tag. At least one of the device hosting the at least one RF backscatter transmitter and the other device hosting the at least one RF backscatter receiver is configured to maintain an inventory of locations of the navigation markers in the given venue.
    Type: Grant
    Filed: September 25, 2019
    Date of Patent: December 1, 2020
    Inventors: Karthikeyan Sundaresan, Eugene Chai, Sampath Rangarajan
  • Publication number: 20200334655
    Abstract: A walk-through gate is provided. The walk-through gate includes at least a first semi-transparent side wall and a second semi-transparent side wall encapsulating a walk-through gate volume having an ingress portion and an egress portion. The walk-through gate further includes a plurality of antennas for wirelessly receiving product identifiers for wireless checkout. At least one of the plurality of antennas is made of a semi-transparent conductive material.
    Type: Application
    Filed: April 15, 2020
    Publication date: October 22, 2020
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20200334654
    Abstract: A walk-through gate is provided. The walk-through gate includes a first semi-transparent side wall and a second semi-transparent side wall encapsulating a walk-through gate volume having an ingress portion and an egress portion. The walk-through gate further includes a plurality of antennas for wirelessly receiving product identifiers for wireless checkout. At least one of the plurality of antennas is made of a semi-transparent conductive material.
    Type: Application
    Filed: March 18, 2020
    Publication date: October 22, 2020
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20200293729
    Abstract: Systems and methods for determining radio-frequency identification (RFID) tag proximity groups are provided. The method includes receiving RFID tag readings from multiple RFID tags. The method includes determining signal strengths of the RFID tag readings. The method includes determining pairs of RFID tags based on the RFID tag readings. The method also includes implementing a twin recurrent neural network (RNN) to determine proximity groups of RFID tags based on distance similarity over time between each of the pairs of the RFID tags.
    Type: Application
    Filed: March 12, 2020
    Publication date: September 17, 2020
    Inventors: Mustafa Arslan, Mohammad Khojastepour, Shasha Li, Sampath Rangarajan
  • Publication number: 20200293040
    Abstract: Systems and methods for localizing and tracking mobile objects are provided. A method includes determining an initial location of a node in a multi-hop network based on multi-lateration from an unmanned aerial vehicle. The method also includes applying an adaptive aperture to address a non-uniform velocity of the node based on the turn and a velocity vector. A determination whether localization for the node can be implemented using first hop nodes in the multi-hop network is made. In response to a determination that localization cannot be implemented using the first hop nodes, inertial sensor measurements associated with the node are accessed and the inertial sensor measurements are integrated with the adaptive aperture to improve localization accuracy.
    Type: Application
    Filed: April 22, 2020
    Publication date: September 17, 2020
    Inventors: Ayon Chakraborty, Karthikeyan Sundaresan, Sampath Rangarajan, Ashutosh Dhekne
  • Publication number: 20200265660
    Abstract: A walk-though gate (WTG) is presented. The WTG includes a WTG structure including a first wall and a second wall, the first and second walls defining a walk though pass way between an entrance and exit, at least one sensor located at the entrance and the exit of a cavity defined by the walk though pass way, at least one first antenna facing toward an inside region of the WTG structure, at least one second antenna facing away from the inside region of the WTG structure, an RFID reader connected to the at least one first and second antennas, and a judgement module to judge if an RFID tag is located inside or outside the walk though gate structure.
    Type: Application
    Filed: November 20, 2019
    Publication date: August 20, 2020
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20200265661
    Abstract: A method includes constructing a WTG structure including a first wall and a second wall, the first and second walls defining a walk though pass way between an entrance and an exit, positioning at least one sensor at the entrance and the exit of a cavity defined by the walk though pass way, positioning at least one first antenna facing toward an inside region of the WTG structure, positioning at least one second antenna facing away from the inside region of the WTG structure, connecting an RFID reader to the at least one first and second antennas, and, judging, via a judgement module, if an RFID tag is located inside or outside the walk though gate structure.
    Type: Application
    Filed: November 20, 2019
    Publication date: August 20, 2020
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20200225319
    Abstract: Devices and systems for implementing a walk-through gate are provided. The devices include a walk-through gate structure having boundaries that have curved inner surfaces on each side of a cavity. The curved inner surfaces are partially covered by a reflective material. The devices include radio frequency (RF) signal transmitters positioned tangent to the curved inner surfaces and RF signal receivers. The devices also include apertures that provide access to the cavity of the walk-through gate structure.
    Type: Application
    Filed: September 23, 2019
    Publication date: July 16, 2020
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan