Patents by Inventor Hamid Jafarkhani

Hamid Jafarkhani 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: 10992353
    Abstract: Communication systems and methods in accordance with various embodiments of the invention utilize modulation on zeros. Carrier frequency offsets (CFO) can result in an unknown rotation of all zeros of a received signal's z-transform. Therefore, a binary MOCZ scheme (BMOCZ) can be utilized in which the modulated binary data is encoded using a cycling register code (e.g. CPC or ACPC), enabling receivers to determine cyclic shifts in the BMOCZ symbol resulting from a CFO. Receivers in accordance with several embodiments of the invention include decoders capable of decoding information bits from received discrete-time baseband signals by: estimating a timing offset for the received signal; determining a plurality of zeros of a z-transform of the received symbol; identifying zeros from the plurality of zeros that encode received bits by correcting fractional rotations resulting from the CFO; and decoding information bits based upon the received bits using a cycling register code.
    Type: Grant
    Filed: September 4, 2020
    Date of Patent: April 27, 2021
    Assignees: California Institute of Technology, The Regents of the University of California, Technische Universität Berlin
    Inventors: Philipp Walk, Babak Hassibi, Peter Jung, Hamid Jafarkhani
  • Publication number: 20210012885
    Abstract: Devices, systems and methods related to techniques for performing four-chamber segmentation of echocardiograms are disclosed. In one example aspect, a method for generating segmented image data based on an input echocardiogram includes receiving an input echocardiogram that includes information associated with four chambers of a heart, performing segmentation on the information associated with the four chambers using an adversarial model that comprises a first artificial neural network with multiple layers, and combining data from selected layers of the first artificial neural network to generate an output image that includes the segmented four chambers of the heart.
    Type: Application
    Filed: July 10, 2020
    Publication date: January 14, 2021
    Inventors: Arghavan Arafati, Hamid Jafarkhani, Arash Kheradvar
  • Publication number: 20200403664
    Abstract: Communication systems and methods in accordance with various embodiments of the invention utilize modulation on zeros. Carrier frequency offsets (CFO) can result in an unknown rotation of all zeros of a received signal's z-transform. Therefore, a binary MOCZ scheme (BMOCZ) can be utilized in which the modulated binary data is encoded using a cycling register code (e.g. CPC or ACPC), enabling receivers to determine cyclic shifts in the BMOCZ symbol resulting from a CFO. Receivers in accordance with several embodiments of the invention include decoders capable of decoding information bits from received discrete-time baseband signals by: estimating a timing offset for the received signal; determining a plurality of zeros of a z-transform of the received symbol; identifying zeros from the plurality of zeros that encode received bits by correcting fractional rotations resulting from the CFO; and decoding information bits based upon the received bits using a cycling register code.
    Type: Application
    Filed: September 4, 2020
    Publication date: December 24, 2020
    Applicants: California Institute of Technology, The Regents of the University of California, Technische Universität Berlin
    Inventors: Philipp Walk, Babak Hassibi, Peter Jung, Hamid Jafarkhani
  • Publication number: 20200382141
    Abstract: Methods and devices are provided for error correction of distributed data in distributed systems using Reed-Solomon codes. In one embodiment, processes are provided for error correction that include receiving a first correction code for data fragments stored in storage nodes, constructing a second correction code responsive to an unavailable storage node of the storage nodes, performing erasure repair of the unavailable storage node, and outputting a corrected data fragment. The first correction code is a Reed-Solomon code represented as a polynomial and the second correction code is represented as a second polynomial with an increased subpacketization size. Processes are configured to account for repair bandwidth and sub-packetization size. Code constructions and repair schemes accommodate different sizes of evaluation points and provide a flexible tradeoff between the subpacketization size repair bandwidth of codes.
    Type: Application
    Filed: May 29, 2020
    Publication date: December 3, 2020
    Applicant: The Regents of the University of California
    Inventors: Zhiying WANG, Weiqi LI, Hamid JAFARKHANI
  • Patent number: 10804982
    Abstract: Communication systems and methods in accordance with various embodiments of the invention utilize modulation on zeros. Carrier frequency offsets (CFO) can result in an unknown rotation of all zeros of a received signal's z-transform. Therefore, a binary MOCZ scheme (BMOCZ) can be utilized in which the modulated binary data is encoded using a cycling register code (e.g. CPC or ACPC), enabling receivers to determine cyclic shifts in the BMOCZ symbol resulting from a CFO. Receivers in accordance with several embodiments of the invention include decoders capable of decoding information bits from received discrete-time baseband signals by: estimating a timing offset for the received signal; determining a plurality of zeros of a z-transform of the received symbol; identifying zeros from the plurality of zeros that encode received bits by correcting fractional rotations resulting from the CFO; and decoding information bits based upon the received bits using a cycling register code.
    Type: Grant
    Filed: February 7, 2020
    Date of Patent: October 13, 2020
    Assignees: California Institute of Technology, The Regents of the University of California, Technische Universität Berlin
    Inventors: Philipp Walk, Babak Hassibi, Peter Jung, Hamid Jafarkhani
  • Publication number: 20200259534
    Abstract: Communication systems and methods in accordance with various embodiments of the invention utilize modulation on zeros. Carrier frequency offsets (CFO) can result in an unknown rotation of all zeros of a received signal's z-transform. Therefore, a binary MOCZ scheme (BMOCZ) can be utilized in which the modulated binary data is encoded using a cycling register code (e.g. CPC or ACPC), enabling receivers to determine cyclic shifts in the BMOCZ symbol resulting from a CFO. Receivers in accordance with several embodiments of the invention include decoders capable of decoding information bits from received discrete-time baseband signals by: estimating a timing offset for the received signal; determining a plurality of zeros of a z-transform of the received symbol; identifying zeros from the plurality of zeros that encode received bits by correcting fractional rotations resulting from the CFO; and decoding information bits based upon the received bits using a cycling register code.
    Type: Application
    Filed: February 7, 2020
    Publication date: August 13, 2020
    Applicants: California Institute of Technology, The Regents of the University of California, Technische Universität Berlin
    Inventors: Philipp Walk, Babak Hassibi, Peter Jung, Hamid Jafarkhani
  • Publication number: 20200118266
    Abstract: A method of detecting whether or not a body chamber has an abnormal structure or function including: (a) providing a stack of images as input to a system comprising one or more hardware processors configured to obtain a stack of medical images comprising at least a representation of the body chamber inside the patient; to obtain a region of interest using a convolutional network trained to locate the body chamber, wherein the region of interest corresponds to the body chamber from each of the medical images; and to infer a shape of the body chamber using a stacked auto-encoder (AE) network trained to delineate the body chamber, wherein the AE network segments the body chamber; (b) operating the system to detect the body chamber in the images using deep convolutional networks trained to locate the body chamber, to infer a shape of the body chamber using a stacked auto-encoder trained to delineate the body chamber, and to incorporate the inferred shape into a deformable model for segmentation; and (c) detecting
    Type: Application
    Filed: December 11, 2019
    Publication date: April 16, 2020
    Inventors: Michael Rashidi Avendi, Hamid Jafarkhani, Arash Kheradvar
  • Patent number: 10521902
    Abstract: Systems and methods are disclosed for automatically segmenting a heart chamber from medical images of a patient. The system may include one or more hardware processors configured to: obtain image data including at least a representation of the patient's heart; obtain a region of interest from the image data; organize the region of interest into an input vector; apply the input vector through a trained graph; obtain an output vector representing a refined region of interest corresponding to the heart based on the application of the input vector through the trained graph; apply a deformable model on the obtained output vector representing the refined region of interest; and identify a segment of a heart chamber from the application of the deformable model on the obtained output vector.
    Type: Grant
    Filed: October 14, 2016
    Date of Patent: December 31, 2019
    Assignee: The Regents of the University of California
    Inventors: Michael Rashidi Avendi, Hamid Jafarkhani, Arash Kheradvar
  • Patent number: 10225114
    Abstract: A wireless system, and particularly, a multiple-input multiple-output (MIMO) wireless communication system is disclosed. The wireless system includes a plurality of (re)configurable antennas and a rate-two space coding design for a MIMO system. The MIMO wireless communication system generally includes M (re)configurable antennas configured to independently transmit or broadcast wireless electromagnetic signals having a frequency in the microwave and/or optical ranges, a controller configured to control the (re)configurable antennas, and an encoder configured to encode information onto the wireless electromagnetic signals. The information comprises codewords having N symbols, and the codewords are expressed in an N×M matrix having a non-zero determinant and in which at least one symbol is associated with a coefficient configured to maximize diversity, maximize coding gain and/or reduce channel fading in the MIMO wireless communication system. M and N are each independently an integer of at least 2.
    Type: Grant
    Filed: October 3, 2016
    Date of Patent: March 5, 2019
    Assignees: CSUB Auxillary For Sponsored Programs Administration, The Regents of the University of California
    Inventors: Vida Vakilian, Hani Mehrpouyan, Hamid Jafarkhani
  • Patent number: 10187088
    Abstract: An apparatus or method for minimizing the total accessing cost, such as minimizing repair bandwidth, delay or the number of hops including the steps of minimizing the number of nodes to be engaged for the recovery process using a polynomial-time solution that determines the optimal number of participating nodes and the optimal set of nodes to be engaged for recovering lost data, where in a distributed database storage system, for example a dynamic system, where the accessing cost or even the number of available nodes are subject to change results in different values for the optimal number of participating nodes. An MDS code is included which can be reused when the number of participating nodes varies without having to change the entire code structure and the content of the nodes.
    Type: Grant
    Filed: April 17, 2015
    Date of Patent: January 22, 2019
    Assignee: The Regents of the University of California
    Inventors: Hamid Jafarkhani, Mahdi Hajiaghayi
  • Patent number: 10116372
    Abstract: A method includes the step of interleaving training and feedback stages in a transmitter and a multiplicity of antennas, wherein the transmitter trains the corresponding ones of the multiplicity of antennas one by one and receives feedback information after training each one of the corresponding ones of the multiplicity of antennas. An apparatus operating using the method includes a multiple-input single-output system with t transmitter antennas, a short-term power constraint P, and target data rate ? where for any t, the same outage probability as a system with perfect transmitter and receiver channel state information is achieved with a feedback rate of R1 bits per channel state and via training R2 transmitter antennas on average, where R1 and R2 are independent of t, and depend only on ? and P.
    Type: Grant
    Filed: May 24, 2017
    Date of Patent: October 30, 2018
    Assignee: The Regents of the University of California
    Inventors: Hamid Jafarkhani, Erdem Koyuncu
  • Patent number: 9875581
    Abstract: The disclosure relates to a method of automatically producing a three-dimensional (3D) segmentation of a heart chamber, the method comprising: obtaining data sets from cardiac magnetic resonance imaging (MRI) or ultrasound, generating a 3D segmentation of the heart chamber from the data sets using an active contour method, modifying the 3D segmentation by adding a plurality of intra-chamber structures; and identifying an enclosing myocardium using the 3D segmentation generated by the method.
    Type: Grant
    Filed: November 2, 2015
    Date of Patent: January 23, 2018
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Hamid Jafarkhani, Mahdi Hajiaghayi, Elliott Groves, Arash Kheradvar
  • Publication number: 20170346541
    Abstract: A method includes the step of interleaving training and feedback stages in a transmitter and a multiplicity of antennas, wherein the transmitter trains the corresponding ones of the multiplicity of antennas one by one and receives feedback information after training each one of the corresponding ones of the multiplicity of antennas. An apparatus operating using the method includes a multiple-input single-output system with t transmitter antennas, a short-term power constraint P, and target data rate ? where for any t, the same outage probability as a system with perfect transmitter and receiver channel state information is achieved with a feedback rate of R1 bits per channel state and via training R2 transmitter antennas on average, where R1 and R2 are independent of t, and depend only on ? and P.
    Type: Application
    Filed: May 24, 2017
    Publication date: November 30, 2017
    Inventors: Hamid Jafarkhani, Erdem Koyuncu
  • Patent number: 9826258
    Abstract: An encoder includes a controller to determine whether macroblocks of a frame of video content are to be processed by intra-frame encoding or by predictive coding. The encoder includes a switch coupled to the controller. The encoder includes an intra-frame unit to receive the macroblocks via the switch when the controller determines to process the macroblocks by intra-frame encoding. The encoder includes a predictive unit to receive the macroblocks via the switch when the controller determines to process the macroblocks by predictive encoding. The encoder also includes a redundancy allocation unit coupled to the controller. The controller determines whether to process the macroblocks by intra-frame encoding or predictive frame encoding based on information received from the redundancy allocation unit.
    Type: Grant
    Filed: August 12, 2014
    Date of Patent: November 21, 2017
    Assignee: AT&T INTELLECTUAL PROPERTY II, L.P.
    Inventors: Michael Orchard, Hamid Jafarkhani, Amy Reibman, Yao Wang
  • Publication number: 20170170997
    Abstract: A wireless system, and particularly, a multiple-input multiple-output (MIMO) wireless communication system is disclosed. The wireless system includes a plurality of (re)configurable antennas and a rate-two space coding design for a MIMO system. The MIMO wireless communication system generally includes M (re)configurable antennas configured to independently transmit or broadcast wireless electromagnetic signals having a frequency in the microwave and/or optical ranges, a controller configured to control the (re)configurable antennas, and an encoder configured to encode information onto the wireless electromagnetic signals. The information comprises codewords having N symbols, and the codewords are expressed in an N×M matrix having a non-zero determinant and in which at least one symbol is associated with a coefficient configured to maximize diversity, maximize coding gain and/or reduce channel fading in the MIMO wireless communication system. M and N are each independently an integer of at least 2.
    Type: Application
    Filed: October 3, 2016
    Publication date: June 15, 2017
    Inventors: Vida Vakilian, Hani Mehrpouyan, Hamid Jafarkhani
  • Publication number: 20170109881
    Abstract: Systems and methods are disclosed for automatically segmenting a heart chamber from medical images of a patient. The system may include one or more hardware processors configured to: obtain image data including at least a representation of the patient's heart; obtain a region of interest from the image data; organize the region of interest into an input vector; apply the input vector through a trained graph; obtain an output vector representing a refined region of interest corresponding to the heart based on the application of the input vector through the trained graph; apply a deformable model on the obtained output vector representing the refined region of interest; and identify a segment of a heart chamber from the application of the deformable model on the obtained output vector.
    Type: Application
    Filed: October 14, 2016
    Publication date: April 20, 2017
    Inventors: Michael Rashidi Avendi, Hamid Jafarkhani, Arash Kheradvar
  • Publication number: 20160140751
    Abstract: The disclosure relates to a method of automatically producing a three-dimensional (3D) segmentation of a heart chamber, the method comprising: obtaining data sets from cardiac magnetic resonance imaging (MRI) or ultrasound, generating a 3D segmentation of the heart chamber from the data sets using an active contour method, modifying the 3D segmentation by adding a plurality of intra-chamber structures; and identifying an enclosing myocardium using the 3D segmentation generated by the method.
    Type: Application
    Filed: November 2, 2015
    Publication date: May 19, 2016
    Inventors: Hamid Jafarkhani, Mahdi Hajiaghayi, Elliott Groves, Arash Kheradvar
  • Publication number: 20150303949
    Abstract: An apparatus or method for minimizing the total accessing cost, such as minimizing repair bandwidth, delay or the number of hops including the steps of minimizing the number of nodes to be engaged for the recovery process using a polynomial-time solution that determines the optimal number of participating nodes and the optimal set of nodes to be engaged for recovering lost data, where in a distributed database storage system, for example a dynamic system, where the accessing cost or even the number of available nodes are subject to change results in different values for the optimal number of participating nodes. An MDS code is included which can be reused when the number of participating nodes varies without having to change the entire code structure and the content of the nodes.
    Type: Application
    Filed: April 17, 2015
    Publication date: October 22, 2015
    Inventors: Hamid Jafarkhani, Mahdi Hajiaghayi
  • Publication number: 20140348225
    Abstract: An encoder includes a controller to determine whether macroblocks of a frame of video content are to be processed by intra-frame encoding or by predictive coding. The encoder includes a switch coupled to the controller. The encoder includes an intra-frame unit to receive the macroblocks via the switch when the controller determines to process the macroblocks by intra-frame encoding. The encoder includes a predictive unit to receive the macroblocks via the switch when the controller determines to process the macroblocks by predictive encoding. The encoder also includes a redundancy allocation unit coupled to the controller. The controller determines whether to process the macroblocks by intra-frame encoding or predictive frame encoding based on information received from the redundancy allocation unit.
    Type: Application
    Filed: August 12, 2014
    Publication date: November 27, 2014
    Inventors: Michael Orchard, Hamid Jafarkhani, Amy Reibman, Yao Wang
  • Patent number: 8891494
    Abstract: A method of multiple packet reception (MPR) using distributed time slot assignment (TDSA) in a multi-user network where receivers can detect two packets at the same time includes the steps of requesting information on slot assignment in a contention area, setting a frame length and acquiring a the slot assignment, selecting the assigned slot, and announcing and confirming information about the frame length and the assigned slot. The step of requesting information on slot assignment, setting a frame length and acquiring a slot assignment, and selecting the assigned slot are performed in a network where receivers can detect two packets at the same time, where time slots are assigned to nodes instead of links, where one-hop neighbors are assigned to different time slots since they may form a link together, while sharing one time slot with one of the two-hop neighbors in a non-interfering assignment.
    Type: Grant
    Filed: October 10, 2011
    Date of Patent: November 18, 2014
    Assignee: The Regents of the University of California
    Inventors: Sanaz Barghi, Hamid Jafarkhani, Homayoun Yousefi'zadeh