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).

  • Patent number: 11651664
    Abstract: Systems and methods for self-checkout at a point-of-sale are provided. The system and method includes using a plurality of radio frequency identification (RFID) transceivers within a store, and an RFID reader configured to receive an RFID code from an RFID tag activated by the plurality of radio frequency identification (RFID) transceivers. The system and method also includes using a classifier configured to determine whether the RFID tag is inside or outside a designated area, wherein the classifier is trained in a manner that a number of items incorrectly identified as being purchased is below a threshold to minimize customer dissatisfaction (CDS) determined as the ratio of the value of items charged to the customer but not purchased by a customer to the total charge to the customer.
    Type: Grant
    Filed: February 9, 2021
    Date of Patent: May 16, 2023
    Assignee: NEC Corporation
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan, Eugene Chai, Carlos Bocanegra
  • Patent number: 11620462
    Abstract: A method for product tagging is presented including emitting, by at least one RF backscatter transmitter, a dual-tone Radio Frequency (RF) signal embedded within a standardized RF signal on a frequency channel, reflecting and frequency shifting, by a passive RF backscatter tag associated with a product, the dual-tone RF signal to a different frequency channel, and reading, by at least one RF backscatter receiver, the product on the different frequency channel by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the dual-tone RF signal by the passive RF backscatter tag.
    Type: Grant
    Filed: March 16, 2021
    Date of Patent: April 4, 2023
    Assignee: NEC Corporation
    Inventors: Karthikeyan Sundaresan, Eugene Chai, Sampath Rangarajan, Mohammad Rostami
  • Patent number: 11620880
    Abstract: Systems and methods for is provided for self-checkout at a point-of-sale. The system and method includes a plurality of radio frequency identification (RFID) transceivers, an RFID reader, wherein the RFID reader is configured to receive a response with an RFID code from each of a plurality of RFID tags activated simultaneously by at least one of the plurality of radio frequency identification (RFID) transceivers, and decode the RFID code from the response received from each of the RFID tags, and a classifier configured to determine whether each of the plurality of RFID tags is inside or outside a walk-through checkout area inside a store, wherein the system calculates an amount charged to a customer based on the cost of the items identified as within the walk-through checkout area.
    Type: Grant
    Filed: February 9, 2021
    Date of Patent: April 4, 2023
    Assignee: NEC Corporation
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan, Eugene Chai, Carlos Bocanegra
  • Patent number: 11595934
    Abstract: Methods and systems for localization within an environment include determining a topology estimate of nodes located in a dynamic indoor environment, based on distances measured between the nodes. Rigid k-core sub-graphs of the topology estimate are generated to determine relative localizations of the nodes. Relative localizations are transformed into absolute localizations to generate a map of positions of the nodes within the environment. A feature of the map is deployed to a device in the environment.
    Type: Grant
    Filed: March 26, 2021
    Date of Patent: February 28, 2023
    Inventors: Ayon Chakraborty, Karthikeyan Sundaresan, Sampath Rangarajan, Md. Shaifur Rahman
  • Patent number: 11580317
    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: Grant
    Filed: March 12, 2020
    Date of Patent: February 14, 2023
    Inventors: Mustafa Arslan, Mohammad Khojastepour, Shasha Li, Sampath Rangarajan
  • Patent number: 11441890
    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: Grant
    Filed: September 18, 2020
    Date of Patent: September 13, 2022
    Inventors: Mohammad Khojastepour, Sampath Rangarajan
  • Patent number: 11415669
    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: Grant
    Filed: September 23, 2019
    Date of Patent: August 16, 2022
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Patent number: 11379676
    Abstract: A method for employing cycle counting is presented. The method includes interrogating, by an RFID reader, RFID tags by using a plurality of antenna ports, determining, by an activation sequencer, an activation sequence of the plurality of antenna ports that have been enabled, collecting RFID tag responses from each of the RFID tags, and matching one or more of the RFID tag responses to a particular antenna port of the plurality of antenna ports in an activation cycle.
    Type: Grant
    Filed: April 1, 2021
    Date of Patent: July 5, 2022
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Patent number: 11354641
    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: Grant
    Filed: March 18, 2020
    Date of Patent: June 7, 2022
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Patent number: 11356172
    Abstract: Systems and methods implementing a multi-unmanned aerial vehicle (UAV) wireless communication network are provided. The system includes application UAVs that wirelessly provide applications. The system includes relay UAVs that connect the application UAVs to a ground station. The ground station connects to a wireless backhaul network. Processor devices determine mobility for the application UAVs based on application-specific objectives. The processor devices also determine mobility for the relay UAVs based on forming and maintaining the wireless backhaul network.
    Type: Grant
    Filed: March 12, 2020
    Date of Patent: June 7, 2022
    Inventors: Eugene Chai, Sampath Rangarajan, Karthikeyan Sundaresan, Ramanujan Sheshadri
  • Publication number: 20220103246
    Abstract: Systems and methods implementing a multi-unmanned aerial vehicle (UAV) wireless communication network are provided. The system includes application UAVs that wirelessly provide applications. The system includes relay UAVs that connect the application UAVs to a ground station. The ground station connects to a wireless backhaul network. Processor devices determine mobility for the application UAVs based on application-specific objectives. The processor devices also determine mobility for the relay UAVs based on forming and maintaining the wireless backhaul network.
    Type: Application
    Filed: March 12, 2020
    Publication date: March 31, 2022
    Inventors: Eugene Chai, Sampath Rangarajan, Karthikeyan Sundaresan, Ramanujan Sheshadri
  • Patent number: 11169518
    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: Grant
    Filed: April 22, 2020
    Date of Patent: November 9, 2021
    Inventors: Ayon Chakraborty, Karthikeyan Sundaresan, Sampath Rangarajan, Ashutosh Dhekne
  • Publication number: 20210312146
    Abstract: A method for employing cycle counting is presented. The method includes interrogating, by an RFID reader, RFID tags by using a plurality of antenna ports, determining, by an activation sequencer, an activation sequence of the plurality of antenna ports that have been enabled, collecting RFID tag responses from each of the RFID tags, and matching one or more of the RFID tag responses to a particular antenna port of the plurality of antenna ports in an activation cycle.
    Type: Application
    Filed: April 1, 2021
    Publication date: October 7, 2021
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20210311504
    Abstract: Systems and methods for automatically constructing a 3-dimensional (3D) model of a feature using a drone. The method includes generating a reconnaissance flight path that minimizes battery usage by the drone, and conducting a discovery flight that uses the reconnaissance flight path. The method further includes transmitting reconnaissance laser sensor data from the drone to a processing system for target identification, and selecting a target feature for 3D model construction based on the reconnaissance laser sensor data. The method further includes scanning the target feature using a laser sensor, transmitting laser sensor data for the target feature having a minimum point density from the drone to the processing system for 3D model construction, and constructing the 3D model from the minimum point density laser sensor data.
    Type: Application
    Filed: April 1, 2021
    Publication date: October 7, 2021
    Inventors: Eugene Chai, Karthikeyan Sundaresan, Sampath Rangarajan
  • Publication number: 20210306977
    Abstract: Methods and systems for localization within an environment include determining a topology estimate of nodes located in a dynamic indoor environment, based on distances measured between the nodes. Rigid k-core sub-graphs of the topology estimate are generated to determine relative localizations of the nodes. Relative localizations are transformed into absolute localizations to generate a map of positions of the nodes within the environment. A feature of the map is deployed to a device in the environment.
    Type: Application
    Filed: March 26, 2021
    Publication date: September 30, 2021
    Inventors: Ayon Chakraborty, Karthikeyan Sundaresan, Sampath Rangarajan, Md. Shaifur Rahman
  • Publication number: 20210294993
    Abstract: A method for product tagging is presented including emitting, by at least one RF backscatter transmitter, a dual-tone Radio Frequency (RF) signal embedded within a standardized RF signal on a frequency channel, reflecting and frequency shifting, by a passive RF backscatter tag associated with a product, the dual-tone RF signal to a different frequency channel, and reading, by at least one RF backscatter receiver, the product on the different frequency channel by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the dual-tone RF signal by the passive RF backscatter tag.
    Type: Application
    Filed: March 16, 2021
    Publication date: September 23, 2021
    Inventors: Karthikeyan Sundaresan, Eugene Chai, Sampath Rangarajan, Mohammad Rostami
  • Patent number: 11120233
    Abstract: A Radio Frequency Identification (RFID) localization system is provided. The system includes a set of passive RFID tags, each for reflecting transmitted signals. The system further includes an RFID reader for detecting the reflected signals by the passive RFID tags. The system also includes a processor for localizing an object in an area based on the reflected signals by computing signatures using probabilistic macro-channels between the RFID reader and locations of the passive RFID tags. The transmitted signals form inputs to the probabilistic macro-channels, and the signatures form outputs from the probabilistic macro-channels.
    Type: Grant
    Filed: April 5, 2019
    Date of Patent: September 14, 2021
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20210248879
    Abstract: Systems and methods for is provided for self-checkout at a point-of-sale. The system and method includes a plurality of radio frequency identification (RFID) transceivers, an RFID reader, wherein the RFID reader is configured to receive a response with an RFID code from each of a plurality of RFID tags activated simultaneously by at least one of the plurality of radio frequency identification (RFID) transceivers, and decode the RFID code from the response received from each of the RFID tags, and a classifier configured to determine whether each of the plurality of RFID tags is inside or outside a walk-through checkout area inside a store, wherein the system calculates an amount charged to a customer based on the cost of the items identified as within the walk-through checkout area.
    Type: Application
    Filed: February 9, 2021
    Publication date: August 12, 2021
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan, Eugene Chai, Carlos Bocanegra
  • Publication number: 20210248580
    Abstract: Systems and methods for self-checkout at a point-of-sale are provided. The system and method includes using a plurality of radio frequency identification (RFID) transceivers within a store, and an RFID reader configured to receive an RFID code from an RFID tag activated by the plurality of radio frequency identification (RFID) transceivers. The system and method also includes using a classifier configured to determine whether the RFID tag is inside or outside a designated area, wherein the classifier is trained in a manner that a number of items incorrectly identified as being purchased is below a threshold to minimize customer dissatisfaction (CDS) determined as the ratio of the value of items charged to the customer but not purchased by a customer to the total charge to the customer.
    Type: Application
    Filed: February 9, 2021
    Publication date: August 12, 2021
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan, Eugene Chai, Carlos Bocanegra
  • Patent number: 11089432
    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: Grant
    Filed: September 12, 2019
    Date of Patent: August 10, 2021
    Inventors: Karthikeyan Sundaresan, Ayon Chakraborty, Sampath Rangarajan, Ashutosh Dhekne