Patents by Inventor Rabih Chrabieh

Rabih Chrabieh 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: 10042037
    Abstract: A technique is provided for estimating time of arrival of a signal transmitted as a pulse and received as a sum of pulses. The received signal is filtered with a novel filter that lowers the early side lobes of the received signal to noise level. A first energy rise point is identified at a point of the main lobe of the filtered received signal, at which the energy is higher than the noise by a predetermined level. Starting from the identification of the first energy rise points, the time of arrival is estimated via curve matching, in which the shape of the filtered received signal is matched to the shape of composed by a sum of one or more reference curves that are shifted both in time and in energy. The reference curves are found by applying to the transmitted signal the same filter applied to the received signal.
    Type: Grant
    Filed: February 19, 2015
    Date of Patent: August 7, 2018
    Assignee: Nestwave SAS
    Inventors: Rabih Chrabieh, Bogdan Franovici
  • Patent number: 9961559
    Abstract: Positioning determination of a communication device in a wireless communication network is supported by a positioning device receiving [230] tight synchronization signals from a master positioning cell; determining [232] therefrom a plurality of time differences between their actual and theoretical times of arrival; synchronizing [234] a positioning cell clock based on the received tight synchronization signals adjusted by the time differences; and emitting [236] to the communication device a positioning signal at a time determined by the synchronization. The positioning signal includes an identifier of the positioning cell, and it is transmitted so as not to interfere with positioning pilot signals transmitted by the wireless communication network. The positioning device may alternatively receive synchronization signals from another positioning cell instead of a master positioning cell.
    Type: Grant
    Filed: October 2, 2017
    Date of Patent: May 1, 2018
    Assignee: Nestwave SAS
    Inventor: Rabih Chrabieh
  • Publication number: 20180027421
    Abstract: Positioning determination of a communication device in a wireless communication network is supported by a positioning device receiving [230] tight synchronization signals from a master positioning cell; determining [232] therefrom a plurality of time differences between their actual and theoretical times of arrival; synchronizing [234] a positioning cell clock based on the received tight synchronization signals adjusted by the time differences; and emitting [236] to the communication device a positioning signal at a time determined by the synchronization. The positioning signal includes an identifier of the positioning cell, and it is transmitted so as not to interfere with positioning pilot signals transmitted by the wireless communication network. The positioning device may alternatively receive synchronization signals from another positioning cell instead of a master positioning cell.
    Type: Application
    Filed: October 2, 2017
    Publication date: January 25, 2018
    Inventor: Rabih Chrabieh
  • Patent number: 9813877
    Abstract: A system for accurate positioning of a communication devices includes a plurality of positioning cells configured for synchronizing to the cellular network and to each other, and for emitting positioning signals during time intervals proximal to time points at which the cellular network emits synchronization signals. In the manner, the positioning signals reach the communication device when the communication device's antenna is on for listening to a synchronization signal of the cellular network. Processing the times of arrival of the positioning signals by a server in communication with the communication device enables accurate positioning of the communication device.
    Type: Grant
    Filed: December 14, 2015
    Date of Patent: November 7, 2017
    Assignee: Nestwave SAS
    Inventor: Rabih Chrabieh
  • Publication number: 20160306027
    Abstract: A technique is provided for estimating time of arrival of a signal transmitted as a pulse and received as a sum of pulses. The received signal is filtered with a novel filter that lowers the early side lobes of the received signal to noise level. A first energy rise point is identified at a point of the main lobe of the filtered received signal, at which the energy is higher than the noise by a predetermined level. Starting from the identification of the first energy rise points, the time of arrival is estimated via curve matching, in which the shape of the filtered received signal is matched to the shape of composed by a sum of one or more reference curves that are shifted both in time and in energy. The reference curves are found by applying to the transmitted signal the same filter applied to the received signal.
    Type: Application
    Filed: February 19, 2015
    Publication date: October 20, 2016
    Inventors: Rabih Chrabieh, Bogdan Franovici, Dirk Slock
  • Patent number: 9281861
    Abstract: Low-power transmitter and/or receiver devices are provided by sacrificing time and/or frequency diversity in exchange for lower power consumption. When channel conditions indicate that time and/or frequency spreading are unnecessary for transmissions, a transmitter may enter into a power-conservation mode in which transmissions are performed using a time gating scheme or a time repetition scheme. In the time gating scheme, symbols are transmitting just once, rather than a plurality of times, but with increased transmission power. In the time repetition scheme, copies of the same symbol are transmitted a plurality of times on the same frequency on different symbol transmission periods, instead of being retransmitted on different frequencies on different symbol transmission periods. Consequently, the symbol can be generated once and stored for subsequent retransmission, thereby allowing some of the transmitter/receiver chain components can be operated at a lower duty cycle or processing speed to conserve power.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: March 8, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Samir Soliman, Ozgur Dural, Krishnan Rajamani, Rabih Chrabieh
  • Patent number: 8867662
    Abstract: Techniques for rotating and transmitting multidimensional constellations are disclosed. A method for rotating a multidimensional constellation may include constructing a first rotation matrix, constructing a second rotation matrix, applying orthogonality constraints to the first and second rotation matrices; selecting an optimizing rotation matrix from the first and second rotation matrices; and rotating the multidimensional constellation using the optimizing rotation matrix. Constructing the first rotation matrix and second rotation matrices may include constructing a first column that includes first matrix elements based on the number of axes in the multidimensional constellation, and additional columns that include permutations of the first matrix elements.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: October 21, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Rabih Chrabieh, Ozgur Dural
  • Patent number: 8737548
    Abstract: An orthogonal frequency division multiplex (OFDM) transmitter may adaptively load each sub-carrier, buffering less than an OFDM frame in order to reduce hardware requirements and latency. The transmitter may use feedback information from the receiver regarding the quality of the sub-carriers. In addition, combining repetition and puncturing to achieve a desired date rate per class further reduces hardware by simplifying or even eliminating an interleaver. Additional mitigation and even performance enhancement techniques are incorporated to address inter-class boundaries within an OFDM frame, such as introducing transition classes. Channel state information may be reported in various formats including full bitmap, changed subchannels, and reported bad subchannels.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: May 27, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Rabih Chrabieh, Samir S. Soliman, Ozgur Dural
  • Patent number: 8724738
    Abstract: Techniques for rotating and transmitting multidimensional constellations are disclosed. A method for rotating a multidimensional constellation may include constructing a first rotation matrix, constructing a second rotation matrix, applying orthogonality constraints to the first and second rotation matrices; selecting an optimizing rotation matrix from the first and second rotation matrices; and rotating the multidimensional constellation using the optimizing rotation matrix. Constructing the first rotation matrix and second rotation matrices may include constructing a first column that includes first matrix dements based on the number of axes in the multidimensional constellation, and additional columns that include permutations of the first matrix elements.
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: May 13, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Rabih Chrabieh, Ozgur Dural
  • Patent number: 8711958
    Abstract: The disclosure relates to a method for decoding a received signal in a MIMO communication system and in at least one layer, each layer carrying at least one data symbol belonging to a signal constellation. The method includes, for one of the at least one layer, a maximum likelihood detection step. This step includes: selecting one candidate value for the data symbol of the layer, and determining the Euclidian distance between the received signal Y and the data signal transmitted using said candidate value multiplied by said channel matrix H, weighted by the inverse of a noise covariance matrix C such as ?Y??iHixi?C?12, expressed as: ?i?n?Hi?C?12|xi|2?2(HiHC?1Y?0.5?j?i,nHiHC?1Hjxj)x*i+?Hn?C?12|xn|2?2(HnHC?1Y??j?nHnHC?1Hjxj)x*n=?i?n?iR(xi)2?2?iRxi+?nR(xn)2?2?nRxn+?i?n?iI(?xi)2?2?iI?xi+?nI(?xn)2?2?nI?xn. The terms depending on ?k are computed by adding to each of them a predetermined constant depending on the size of the constellation of the layer k, called a constellation dependent constant.
    Type: Grant
    Filed: August 29, 2012
    Date of Patent: April 29, 2014
    Assignee: Sequans Communications
    Inventors: Rabih Chrabieh, Yang Liu
  • Publication number: 20140062733
    Abstract: The disclosure relates to a method for decoding a received signal in a MIMO communication system and in at least one layer, each layer carrying at least one data symbol belonging to a signal constellation. The method includes, for one of the at least one layer, a maximum likelihood detection step. This step includes: selecting one candidate value for the data symbol of the layer, and determining the Euclidian distance between the received signal Y and the data signal transmitted using said candidate value multiplied by said channel matrix H, weighted by the inverse of a noise covariance matrix C such as ?Y??iHixi?C?12 expressed as: ?i?n?C?12|xi|2?2(HiHC?1Y?0.5?j?i,nHiHC?1Hjxj)xi*+?Hn?C?12|xn|2?2(HnHC?1Y??j?nHnHC?1Hjxj)xn*=?i?n?iR(xi)2?2?iRxi+?nR(xn)2?2?nRxn+?i?n?iI(?xi)2?2?iI?xi+?nI(?xn)2?2?nI?xn. The terms depending on ?k are computed by adding to each of them a predetermined constant depending on the size of the constellation of the layer k, called a constellation dependent constant.
    Type: Application
    Filed: August 29, 2012
    Publication date: March 6, 2014
    Applicant: SEQUANS COMMUNICATIONS
    Inventors: Rabih Chrabieh, Yang Liu
  • Patent number: 8553790
    Abstract: Low-power transmitter and/or receiver devices are provided by sacrificing time and/or frequency diversity in exchange for lower power consumption. When channel conditions indicate that time and/or frequency spreading are unnecessary for transmissions, a transmitter may enter into a power-conservation mode in which transmissions are performed using a time gating scheme or a time repetition scheme. In the time gating scheme, symbols are transmitting just once, rather than a plurality of times, but with increased transmission power. In the time repetition scheme, copies of the same symbol are transmitted a plurality of times on the same frequency on different symbol transmission periods, instead of being retransmitted on different frequencies on different symbol transmission periods. Consequently, the symbol can be generated once and stored for subsequent retransmission, thereby allowing some of the transmitter/receiver chain components can be operated at a lower duty cycle or processing speed to conserve power.
    Type: Grant
    Filed: January 24, 2012
    Date of Patent: October 8, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Samir Soliman, Ozgur Dural, Krishnan Rajamani, Rabih Chrabieh
  • Patent number: 8526543
    Abstract: A system and method are provided for removing quadrature imbalance errors in received data. The method accepts an unbiased training sequence in a quadrature demodulation receiver. An unbiased training sequence has a uniform accumulated power evenly distributed in a complex plane, and includes predetermined reference signals (p) at frequency +f and predetermined mirror signals (pm) at frequency ?f. The unbiased training sequence is processed, generating a sequence of processed symbols (y) at frequency +f, representing complex plane information in the unbiased training sequence. Each processed symbol (y) is multiplied by the mirror signal (pm), and an unbiased quadrature imbalance estimate Bm is obtained at frequency (?f). Using quadrature imbalance estimates, channel estimates, and processed symbols, an imbalance-corrected symbol can be generated.
    Type: Grant
    Filed: July 11, 2011
    Date of Patent: September 3, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Rabih Chrabieh, Samir S Soliman
  • Patent number: 8488691
    Abstract: An orthogonal frequency division multiplex (OFDM) transmitter may adaptively load each sub-carrier, buffering less than an OFDM frame in order to reduce hardware requirements and latency. The transmitter may use feedback information from the receiver regarding the quality of the sub-carriers. In addition, combining repetition and puncturing to achieve a desired date rate per class further reduces hardware by simplifying or even eliminating an interleaver. Additional mitigation and even performance enhancement techniques are incorporated to address inter-class boundaries within an OFDM frame, such as introducing transition classes. Channel state information may be reported in various formats including full bitmap, changed subchannels, and reported bad subchannels.
    Type: Grant
    Filed: November 7, 2008
    Date of Patent: July 16, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Rabih Chrabieh, Samir S. Soliman, Ozgur Dural
  • Patent number: 8446967
    Abstract: A method is provided to generate preamble sequences. The method includes transmitting a periodic set of samples as part of a wireless communications preamble sequence and determining a set of null periods in which zero samples are transmitted. The null periods are interspersed among the periodic set of samples in order to enhance correlation efficiency and mitigate processing complexity.
    Type: Grant
    Filed: January 8, 2009
    Date of Patent: May 21, 2013
    Assignee: QUALCOMM Incorporated
    Inventor: Rabih Chrabieh
  • Patent number: 8428175
    Abstract: A system and method are provided for transmitting a rotating training sequence. A rotating training signal is generated in quadrature modulation transmitter. The rotating training signal includes training information sent via an in-phase (I) modulation path, as well as training information sent via a quadrature (Q) modulation path. The rotating training signal may be generated by initially sending training information via the I modulation path, and subsequently sending training information via the Q modulation path. The training information sent via the I modulation path may include a first symbol having a reference phase (e.g., 0 degrees or 180 degrees). Then, the training information sent via the Q modulation path would include a second symbol having a phase that is ±90 from the reference phase.
    Type: Grant
    Filed: March 9, 2007
    Date of Patent: April 23, 2013
    Assignee: QUALCOMM Incorporated
    Inventor: Rabih Chrabieh
  • Patent number: 8352843
    Abstract: An apparatus for coding a communication signal is provided. The apparatus includes an encoder configured to encode the communication signal, to increase the length of the communication signal, and a repetition coder configured to repetitively code part of the encoded communication signal, to utilize at least some of the increased length of the communication signal. The apparatus further includes an interleaver configured to interleave the repetitively coded communication signal. A method is also provided for coding a communication signal.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: January 8, 2013
    Assignee: Qualcomm Incorporated
    Inventors: Rabih Chrabieh, Koorosh Akhavan
  • Patent number: 8290083
    Abstract: A system and method are provided for transmitting an unbiased communications training sequence. The method generates an unbiased training sequence in a quadrature modulation transmitter. The unbiased training sequence represents a uniform accumulated power evenly distributed in the complex plane. As a result, training information in the time domain is sent via an in-phase (I) modulation path having an accumulated power. Training information in the time domain is sent via a quadrature (Q) modulation path having an accumulated power equal to the I modulation path power. Also provided are system and method for calculating an unbiased channel estimate from a received unbiased training sequence.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: October 16, 2012
    Assignee: Qualcomm Incorporated
    Inventor: Rabih Chrabieh
  • Publication number: 20120177138
    Abstract: Techniques for rotating and transmitting multidimensional constellations are disclosed. A method for rotating a multidimensional constellation may include constructing a first rotation matrix, constructing a second rotation matrix, applying orthogonality constraints to the first and second rotation matrices; selecting an optimizing rotation matrix from the first and second rotation matrices; and rotating the multidimensional constellation using the optimizing rotation matrix. Constructing the first rotation matrix and second rotation matrices may include constructing a first column that includes first matrix dements based on the number of axes in the multidimensional constellation, and additional columns that include permutations of the first matrix elements.
    Type: Application
    Filed: March 20, 2012
    Publication date: July 12, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Rabih Chrabieh, Ozgur Dural
  • Publication number: 20120128035
    Abstract: Low-power transmitter and/or receiver devices are provided by sacrificing time and/or frequency diversity in exchange for lower power consumption. When channel conditions indicate that time and/or frequency spreading are unnecessary for transmissions, a transmitter may enter into a power-conservation mode in which transmissions are performed using a time gating scheme or a time repetition scheme. In the time gating scheme, symbols are transmitting just once, rather than a plurality of times, but with increased transmission power. In the time repetition scheme, copies of the same symbol are transmitted a plurality of times on the same frequency on different symbol transmission periods, instead of being retransmitted on different frequencies on different symbol transmission periods. Consequently, the symbol can be generated once and stored for subsequent retransmission, thereby allowing some of the transmitter/receiver chain components can be operated at a lower duty cycle or processing speed to conserve power.
    Type: Application
    Filed: January 24, 2012
    Publication date: May 24, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Samir Soliman, Ozgur Dural, Krishnan Rajamani, Rabih Chrabieh