Patents by Inventor Mohammad A. Khojastepour

Mohammad A. Khojastepour 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: 10997488
    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 plurality of passive RF backscatter tags, each associated with a respective product and configured to reflect and frequency shift the RF signal to a respective different frequency. The product tagging system also includes at least one RF backscatter receiver configured to read the respective product on the respective different frequency by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the RF signal by a corresponding one of the plurality of passive RF backscatter tags.
    Type: Grant
    Filed: March 20, 2020
    Date of Patent: May 4, 2021
    Inventor: Mohammad Khojastepour
  • 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
  • Patent number: 10931352
    Abstract: A method for establishing communication links in a millimeter wave network is presented. The method includes determining an active communication link between first and second devices, the first device transmitting probing packets to the second device, employing a beam search technique to locate narrow beams by triggering the first device to adjust its transmission pattern to cover a fraction of an angular uncertainty region (AUR) at a beginning of a time-slot, and adjusting transmission coefficients of the first device based on a response received from the second device such that if the second device receives a probing packet, the second device sends an acknowledgment packet to the first device and the first device updates the AUR such that the AUR is set to a probed angular interval, and if the second device does not receive the probing packet, the first device updates the AUR to a complementary part of the probed interval.
    Type: Grant
    Filed: October 2, 2019
    Date of Patent: February 23, 2021
    Inventors: Shahram Shahsavari, Mohammad Khojastepour
  • 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
  • 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: 20200334513
    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 plurality of passive RF backscatter tags, each associated with a respective product and configured to reflect and frequency shift the RF signal to a respective different frequency. The product tagging system also includes at least one RF backscatter receiver configured to read the respective product on the respective different frequency by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the RF signal by a corresponding one of the plurality of passive RF backscatter tags.
    Type: Application
    Filed: March 20, 2020
    Publication date: October 22, 2020
    Inventor: Mohammad Khojastepour
  • Publication number: 20200334424
    Abstract: A product tagging system is provided that includes at least one RF backscatter transmitter configured to emit a Radio Frequency (RF) signal on a frequency. The system includes a plurality of passive RF backscatter tags, each associated with a respective product and configured to backscatter a reply in response to a transmission from the transmitter. The system includes at least one RF backscatter receiver configured to read data for the respective product by detecting a distributed ambient backscatter signal generated by backscattering the RF signal by a corresponding one of the tags. The at least one RF backscatter receiver includes at least two antennas for performing Simultaneous Multi-Port reception (SMP) by receiving respective distributed ambient backscatter signals from a same one of the tags responsive to a same one of the RF signal being transmitted thereto. Each of the transmitter and receiver include a respective synchronized clock for the SMP.
    Type: Application
    Filed: April 14, 2020
    Publication date: October 22, 2020
    Inventor: Mohammad Khojastepour
  • 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
  • Patent number: 10795011
    Abstract: A system, method, and computer program product are provided for estimating a distance to an object. The system includes a transmitter for transmitting RF signals from a location of an object. The system further includes measurement equipment, including a receiver, for receiving the transmitted RF signals as corresponding received RF signals and measuring a plurality of phase differences at different frequencies between the transmitted RF signals and the corresponding received RF signals. The system also includes a processor. The processor is configured to calculate normalized phases from the plurality of phase differences. The processor is further configured to calculate corrected phases by resolving one or more ambiguities from the normalized phases. The processor is also configured to obtain a characteristic curve using the corrected phases. The processor is additionally configured to provide an estimate of the distance based on the characteristic curve and the corrected phases.
    Type: Grant
    Filed: February 8, 2018
    Date of Patent: October 6, 2020
    Assignee: NEC Corporation
    Inventors: Mohammad Khojastepour, Mustafa Arslan
  • 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: 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: 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
  • Patent number: 10739452
    Abstract: A system, method, and computer program product are provided for estimating a distance to an object. The system includes a transmitter for transmitting RF signals from a location of an object. The system further includes measurement equipment, including a receiver, for receiving the transmitted RF signals as corresponding received RF signals and measuring a plurality of phase differences at different frequencies between the transmitted RF signals and the corresponding received RF signals. The system also includes a processor. The processor is configured to calculate corrected phases by resolving one or more ambiguities from the plurality of phase differences. The processor is further configured to obtain a characteristic curve using the corrected phases. The processor is also configured to provide an estimate of the distance based on the characteristic curve and the corrected phases.
    Type: Grant
    Filed: February 8, 2018
    Date of Patent: August 11, 2020
    Assignee: NEC Corporation
    Inventors: Mohammad Khojastepour, Mustafa Arslan
  • 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
  • Publication number: 20200226331
    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: Application
    Filed: September 10, 2019
    Publication date: July 16, 2020
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Patent number: 10677906
    Abstract: A system is provided for resolving ambiguity in a phase measurement used in a distance estimation for an object. The system includes a transmitter for transmitting RF signals from an object location. The system includes measurement equipment for receiving the transmitted RF signals as corresponding received RF signals and measuring a plurality of phases at different frequencies between the transmitted RF signals and the corresponding received RF signals. The system includes a processor. The processor is configured to calculate normalized phases from the plurality of measured phases. The processor is configured to perform an intra-frequency ambiguity resolution process that resolves an ambiguity for the normalized phases for a single frequency using an ambiguity factor.
    Type: Grant
    Filed: February 8, 2018
    Date of Patent: June 9, 2020
    Assignee: NEC Corporation
    Inventors: Mohammad Khojastepour, Mustafa Arslan
  • Publication number: 20200119792
    Abstract: A method for establishing communication links in a millimeter wave network is presented. The method includes determining an active communication link between first and second devices, the first device transmitting probing packets to the second device, employing a beam search technique to locate narrow beams by triggering the first device to adjust its transmission pattern to cover a fraction of an angular uncertainty region (AUR) at a beginning of a time-slot, and adjusting transmission coefficients of the first device based on a response received from the second device such that if the second device receives a probing packet, the second device sends an acknowledgment packet to the first device and the first device updates the AUR such that the AUR is set to a probed angular interval, and if the second device does not receive the probing packet, the first device updates the AUR to a complementary part of the probed interval.
    Type: Application
    Filed: October 2, 2019
    Publication date: April 16, 2020
    Inventors: Shahram Shahsavari, Mohammad Khojastepour
  • Patent number: 10616880
    Abstract: In a wireless communications system including a first transmission point and a second transmission point, a wireless communications method implemented in the first transmission point supporting coordinated multi-point transmission and reception (CoMP) is disclosed. The wireless communications method comprises transmitting to the second transmission point one or more CoMP hypothesis sets, and transmitting to the second transmission point a benefit metric corresponding to each CoMP hypothesis set, wherein the benefit metric can be a negative value. Other methods, systems, and apparatuses also are disclosed.
    Type: Grant
    Filed: December 29, 2017
    Date of Patent: April 7, 2020
    Assignee: NEC Corporation
    Inventors: Narayan Prasad, Mohammad Khojastepour, Mustafa Arslan, Karthikeyan Sundaresan, Sampath Rangarajan
  • Patent number: 10594372
    Abstract: A method implemented in a base station used in a wireless communications system is disclosed. The method comprises having 1-layer, 2-layer, 3-layer, and 4-layer codebooks for 4 transmit antenna (4TX) transmission, each codebook including a plurality of precoding matrices, precoding data with one of the plurality of precoding matrices, and transmitting, to a user equipment, the precoded data, wherein each of the 1-layer and 2-layer codebooks comprises a first codebook and a second codebook, and wherein each precoding matrix in the first codebook comprises a first index and a second index. Other apparatuses, systems, and methods also are disclosed.
    Type: Grant
    Filed: February 21, 2019
    Date of Patent: March 17, 2020
    Assignee: NEC Corporation
    Inventors: Narayan Prasad, Guosen Yue, Mohammad Khojastepour, Sampath Rangarajan