Patents by Inventor Mohammad Khojastepour

Mohammad 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: 10234550
    Abstract: A system, method, and computer program product are provided for estimating a distance. The system includes a Radio Frequency Identifier (RFID) reader. The system further includes an RFID tag. The system also includes measurement equipment for measuring a plurality of phase differences at different frequencies between transmitted Radio Frequency (RF) signals from the RFID reader and corresponding received RF signals at the RFID tag. The system additionally 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: March 19, 2019
    Assignee: NEC Corporation
    Inventors: Mohammad Khojastepour, Mustafa Arslan
  • Patent number: 10230507
    Abstract: In a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the first base station supporting coordinated multi-point transmission and reception (CoMP) is disclosed. The wireless communications method comprises receiving from the second base station an information element (IE) indicating multiple relative narrowband Tx (transmit) power (RNTP) thresholds, and performing interference aware scheduling. Other methods, systems, and apparatuses also are disclosed.
    Type: Grant
    Filed: September 16, 2015
    Date of Patent: March 12, 2019
    Assignee: NEC Corporation
    Inventors: Narayan Prasad, Mohammad Khojastepour, Sampath Rangarajan
  • Patent number: 10224986
    Abstract: In a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the first base station supporting coordinated multi-point transmission and reception (CoMP) is disclosed. The wireless communications method comprises, for a given user equipment (UE) identification (ID) and a given channel state information (CSI) process, receiving from the second base station a plurality of CSI reports each of which comprises a rank indication (RI) and a channel quality indicator (CQI), wherein the second base station receives from one or more user equipments (UEs) RI and CQI information. Other methods, systems, and apparatuses also are disclosed.
    Type: Grant
    Filed: September 16, 2015
    Date of Patent: March 5, 2019
    Assignee: NEC Corporation
    Inventors: Narayan Prasad, Mohammad Khojastepour, Sampath Rangarajan
  • Publication number: 20190045580
    Abstract: A system for implementing a distributed core architecture of a wireless communication network is provided. The system includes a plurality of devices configured to communicate with one or more UE devices to implement the wireless communication network. A given one of the plurality of devices includes at least one processor operatively coupled to a memory and a core agent implemented by the at least one processor. The core agent includes a controller for controlling functionality of the device, a switch operatively coupled to the controller, a precomputed policy data store for storing precomputed policies associated with at least security and service, mobility and policy applications, and a set of core applications including an inter-agent communication application for communicating with other core agents associated with other devices of the wireless communication network, and a control application for controlling the device.
    Type: Application
    Filed: July 17, 2018
    Publication date: February 7, 2019
    Inventors: Eugene Chai, Mohammad Khojastepour, Karthikeyan Sundaresan, Sampath Rangarajan, Mehrdad Moradi
  • Publication number: 20190036786
    Abstract: A method implemented in wireless communication systems for finding a topology of a network of communication nodes is presented. The method includes defining a set of the communication nodes as measurement nodes that identify if a channel is available or occupied at a particular time, determining, via a central controller that has access to measurements of at least one measurement node of the measurement nodes, a probability of availability or occupancy of the channel for the at least one measurement node and determining a joint probability of availability or occupancy of the channel for multiple measurement nodes for which a measurement is available, and computing, via a central decision device, the network topology from the determined probabilities.
    Type: Application
    Filed: July 24, 2018
    Publication date: January 31, 2019
    Inventors: Mohammad Khojastepour, Karthikeyan Sundaresan, Eugene Chai, Sampath Rangarajan
  • Publication number: 20190036629
    Abstract: A computer-implemented method executed on a processor for employing an epoch-based approach to estimating interference in an unlicensed spectrum is presented. The method includes enabling communication between a long-term evolution (LTE) evolved node B (eNodeB) and a plurality of clients, detecting and measuring the interference in all existing non-overlapping channels, via the LTE eNodeB, caused by one or more hidden clients of the plurality of clients, collecting interference statistics from all of the plurality of clients across all different channels, and leveraging interference-awareness resulting in channel access performance improvement at a macro-time scale and a micro-time scale.
    Type: Application
    Filed: July 19, 2018
    Publication date: January 31, 2019
    Inventors: Karthikeyan Sundaresan, Eugene Chai, Ramanujan Sheshadri, Mohammad Khojastepour, Sampath Rangarajan
  • Patent number: 10110293
    Abstract: Systems and methods for full-duplex communication in a communications network, including generating a combined channel matrix including two or more channel matrices and determining a null space and a basis for the combined channel matrix. Common, individual, and disjoint vector spaces are determined, and common vector space is determined for each of one or more receiving nodes and each or one or more transmitting nodes, disjoint vector spaces for each of the one or more nodes are determined based on the common vector space for each of the one or more nodes, and individual vector spaces are determined based on the common and the disjoint vector spaces. Signals are mapped at each of the nodes to determine corresponding vector spaces; and interference alignment is performed in common vector spaces and zero forcing in disjoint vector spaces using a hardware processor.
    Type: Grant
    Filed: June 17, 2015
    Date of Patent: October 23, 2018
    Assignee: NEC Corporation
    Inventors: Mohammad Khojastepour, Karthikeyan Sundaresan
  • Patent number: 10091114
    Abstract: Methods and systems of asynchronous access and synchronous transmission include transmitting an initial reservation packet using a first protocol to prevent other devices that use the first protocol from transmitting during a reserved duration. A carrier using a second protocol is activated. Information is transmitted using a second protocol during the reserved duration. During a last subframe of the reserved duration, an additional reservation packet is transmitted using the first protocol to extend the reserved duration. The transmission of the additional reservation packet takes place while the carrier using the second protocol is still active.
    Type: Grant
    Filed: March 1, 2016
    Date of Patent: October 2, 2018
    Assignee: NEC Corporation
    Inventors: Eugene Chai, Karthikeyan Sundaresan, Mohammad Khojastepour, Sampath Rangarajan, Krishna Garikipati
  • Publication number: 20180270849
    Abstract: A system is provided for speculative scheduling that includes a base station having a processor. The processor computes an overall schedule for a set of clients. The overall schedule is formed from a set of speculative schedules, is configured to maximize unlicensed spectrum usage, and is computed by (a) determining a speculative schedule for each resource block from a set of resource blocks in a given sub-frame based on statistics determined for the clients individually and jointly, and (b) selecting, for formation into the overall schedule, (i) a particular resource block and (ii) the speculative schedule for the particular resource block, that yield the maximum incremental utility relative to already determined speculative schedules for other resource blocks in the set, based on criteria including uplink access statistics. The processor executes the overall schedule responsive to a completion of the speculative schedule determination for each resource block in the given sub-frame.
    Type: Application
    Filed: March 8, 2018
    Publication date: September 20, 2018
    Inventors: Karthikeyan Sundaresan, Eugene Chai, Mohammad Khojastepour, Sampath Rangarajan
  • Publication number: 20180270690
    Abstract: A system, method, and computer program product are provided for blue-printing interference for mobile access in an unlicensed spectrum of a synchronous scheduled cellular access system. The system includes a cellular base station having a processor. The processor constructs and executes an intelligent measurement schedule of clients for uplink transmissions to obtain access measurements for the uplink transmissions. The intelligent measurement schedule is constructed for scalable access measurement overhead. The access measurements indicate interference dependencies between the clients. The processor estimates an interference topology and statistics of the interference topology, from the access measurements to form an interference blueprint. The processor adjusts the intelligent measurement schedule to overschedule the clients for the uplink transmissions to reduce spectrum utilization loss while minimizing client transmission collisions, based on the interference blueprint.
    Type: Application
    Filed: March 8, 2018
    Publication date: September 20, 2018
    Inventors: Karthikeyan Sundaresan, Eugene Chai, Mohammad Khojastepour, Sampath Rangarajan
  • Publication number: 20180247092
    Abstract: A method for detecting RFID tags attached to items positioned at a radio frequency identification (RFID) self-service checkout station is presented. The method includes creating one or more virtual shields at the RFID self-service checkout station, the one or more virtual shields defining checkout bins, associating RFID readers to the checkout bins, and enabling an RFID reader associated with the checkout bins to differentiate between RFID tags attached to items positioned inside a checkout bin and RFID tags attached to items positioned outside the checkout bin by at least determining a signal strength of each RFID tag detected by the RFID reader and estimating, based on an outcome of the signal strength of each RFID tag, a distance between each RFID reader and each RFID tag.
    Type: Application
    Filed: February 23, 2018
    Publication date: August 30, 2018
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20180246197
    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: Application
    Filed: February 8, 2018
    Publication date: August 30, 2018
    Inventors: Mohammad Khojastepour, Mustafa Arslan
  • Publication number: 20180247094
    Abstract: A system, method, and computer program product are provided for estimating a distance. The system includes a Radio Frequency Identifier (RFID) reader. The system further includes an RFID tag. The system also includes measurement equipment for measuring a plurality of phase differences at different frequencies between transmitted Radio Frequency (RF) signals from the RFID reader and corresponding received RF signals at the RFID tag. The system additionally 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: Application
    Filed: February 8, 2018
    Publication date: August 30, 2018
    Inventors: Mohammad Khojastepour, Mustafa Arslan
  • Publication number: 20180246186
    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: Application
    Filed: February 8, 2018
    Publication date: August 30, 2018
    Inventors: Mohammad Khojastepour, Mustafa Arslan
  • Publication number: 20180246198
    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: Application
    Filed: February 8, 2018
    Publication date: August 30, 2018
    Inventors: Mohammad Khojastepour, Mustafa Arslan
  • Patent number: 10056947
    Abstract: In a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the first base station supporting coordinated multi-point transmission and reception (CoMP) is disclosed. The wireless communications method comprises, for a given user equipment (UE) identification (ID) and a given channel state information (CSI) process, receiving from the second base station a plurality of CSI reports each of which comprises a rank indication (RI) and a channel quality indicator (CQI), wherein the second base station receives from one or more user equipments (UEs) RI and CQI information. Other methods, systems, and apparatuses also are disclosed.
    Type: Grant
    Filed: September 16, 2015
    Date of Patent: August 21, 2018
    Assignee: NEC Corporation
    Inventors: Narayan Prasad, Mohammad Khojastepour, Sampath Rangarajan
  • Publication number: 20180225967
    Abstract: Systems and methods for detecting occupancy of at least one parking space by a vehicle are described. Detecting occupancy of at least one parking space includes at least one tag device fixed to a respective one of the at least one parking space. A first reader device is configured to interrogated the at least one tag device and detect a reply signal from the at least one tag device. A processor is configured to analyze the reply signal from the tag device including analyzing a received signal strength indication and a differential phase change of the reply signal to determine the presence of a vehicle in the parking space due to interference of the received signal by a signal blocking body.
    Type: Application
    Filed: January 18, 2018
    Publication date: August 9, 2018
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20180213415
    Abstract: A computer-implemented method executed in a wireless communication system for establishing communication links in a millimeter wave network is presented. The method includes determining active communication links between a plurality of transmitters and a plurality of receivers operated by a plurality of users and formulating a quality of service (QoS) proportional fairness (PF) network utility as a constrained submodular set function maximization problem. The method further includes performing an optimization framework by optimizing, based on the active communication links, user association for fixed transmit beam patterns and optimizing, based on the active communication links, the fixed transmit beam patterns and corresponding beam attributes for a fixed set of user associations.
    Type: Application
    Filed: January 18, 2018
    Publication date: July 26, 2018
    Inventors: Mohammad Khojastepour, Narayan Prasad, Sampath Rangarajan, Yasaman Ghasempour
  • Publication number: 20180211519
    Abstract: Systems and methods for detecting occupancy of at least one parking space by a vehicle are described. Detecting occupancy of at least one parking space includes at least one tag device fixed to a respective one of the at least one parking space. A first reader device is configured to interrogated the at least one tag device and detect a reply signal from the at least one tag device. A processor is configured to analyze the reply signal from the tag device including analyzing a received signal strength indication and a differential phase change of the reply signal to determine the presence of a vehicle in the parking space due to interference of the received signal by a signal blocking body.
    Type: Application
    Filed: January 18, 2018
    Publication date: July 26, 2018
    Inventors: Mohammad Khojastepour, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20180198577
    Abstract: Methods and systems for assigning users to nodes include assigning user devices to respective macro nodes in a wireless network. Each of the user devices is assigned to a respective pico node in the wireless network. Each respective pico node is associated with the same macro node that the respective user device is assigned to. Resource allocation fractions are assigned to all pico nodes and all macro nodes in the wireless network based on the assignment of each of the plurality of user devices respective macro nodes and pico nodes.
    Type: Application
    Filed: January 10, 2018
    Publication date: July 12, 2018
    Inventors: Narayan Prasad, Mohammad Khojastepour, Sampath Rangarajan