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: 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: 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: 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: 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: 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
  • 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
  • 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
  • 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: 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: 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: 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