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: 8009750
    Abstract: A receiver window for symbol extraction is provided. A symbol is spread across a plurality of sub-carriers of a frequency band for transmission. If the frequency band is affected by narrowband interference, the receiver window concentrates the narrowband interference energy to minimize its effect on distant sub-carriers within the frequency band. The receiver window is shaped for extracting the symbol from the frequency band, wherein the receiver window has a starting point before the start of the symbol. The receiver window overlaps a previous receiver window for the previous adjacent symbol on the same frequency band. The receiver window is shaped by overlapping and adding a channel impulse response segment from a zero-padded portion of the symbol to the beginning of the symbol and overlapping and adding a second portion from the previous zero-padded symbol (from the same frequency band) to the end of the symbol.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: August 30, 2011
    Assignee: QUALCOMM, Incorporated
    Inventors: Rabih Chrabieh, Samir S. Soliman
  • Patent number: 7983356
    Abstract: A system and method are provided for using frequency domain spreading to generate real signals in the time domain. The method supplies a first complex frequency domain symbol (?) and a second complex frequency domain symbol (?i), and maps (?+j?i) onto a subcarrier (+f). Further, (??j?i)* is mapped onto a mirror subcarrier (?f). The mappings are converted into a complex time domain symbol carrying ? and j?i in a single inverse fast Fourier transformation (IFFT). The real component of the complex time domain symbol (?) is initially supplied, and subsequently supplied is an imaginary component of the complex time domain symbol (?i). The real symbol component (?) is supplied by carrying ? on the subcarrier (+f), and carrying (?)* on the mirror subcarrier (?f). The imaginary symbol component ?i is supplied by carrying ?i on the subcarrier (+f), and carrying (?i)* on the mirror subcarrier (?f).
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: July 19, 2011
    Assignee: QUALCOMM, Incorporated
    Inventors: Rabih Chrabieh, Samir S. Soliman
  • Publication number: 20100202493
    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: February 12, 2009
    Publication date: August 12, 2010
    Applicant: QUALCOMM INCORPORATED
    Inventors: Samir Soliman, Ozgur Dural, Krishnan Rajamani, Rabih Chrabieh
  • Publication number: 20100172423
    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: Application
    Filed: January 8, 2009
    Publication date: July 8, 2010
    Applicant: QUALCOMM Incorporated
    Inventor: Rabih Chrabieh
  • Publication number: 20100086066
    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: Application
    Filed: November 7, 2008
    Publication date: April 8, 2010
    Applicant: QUALCOMM Incorporated
    Inventors: Rabih Chrabieh, Samir S. Soliman, Ozgur Dural
  • Publication number: 20090245401
    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: Application
    Filed: March 27, 2009
    Publication date: October 1, 2009
    Applicant: QUALCOMM Incorporated
    Inventors: Rabih Chrabieh, Ozgur Dural
  • Publication number: 20090161804
    Abstract: A receiver window for symbol extraction is provided. A symbol is spread across a plurality of sub-carriers of a frequency band for transmission. If the frequency band is affected by narrowband interference, the receiver window concentrates the narrowband interference energy to minimize its effect on distant sub-carriers within the frequency band. The receiver window is shaped for extracting the symbol from the frequency band, wherein the receiver window has a starting point before the start of the symbol. The receiver window overlaps a previous receiver window for the previous adjacent symbol on the same frequency band. The receiver window is shaped by overlapping and adding a channel impulse response segment from a zero-padded portion of the symbol to the beginning of the symbol and overlapping and adding a second portion from the previous zero-padded symbol (from the same frequency band) to the end of the symbol.
    Type: Application
    Filed: December 21, 2007
    Publication date: June 25, 2009
    Applicant: QUALCOMM Incorporated
    Inventors: Rabih Chrabieh, Samir S. Soliman
  • Publication number: 20090004984
    Abstract: A system and method are provided for using frequency domain spreading to generate real signals in the time domain. The method supplies a first complex frequency domain symbol (?) and a second complex frequency domain symbol (?i), and maps (?+j?i) onto a subcarrier (+f). Further, (??j?i)* is mapped onto a mirror subcarrier (?f). The mappings are converted into a complex time domain symbol carrying ? and j?i in a single inverse fast Fourier transformation (IFFT). The real component of the complex time domain symbol (?) is initially supplied, and subsequently supplied is an imaginary component of the complex time domain symbol (?i). The real symbol component (?) is supplied by carrying a on the subcarrier (+f), and carrying (?)* on the mirror subcarrier (?f). The imaginary symbol component ?i is supplied by carrying ?i on the subcarrier (+f), and carrying (?i)* on the mirror subcarrier (?f).
    Type: Application
    Filed: June 29, 2007
    Publication date: January 1, 2009
    Applicant: QUALCOMM INCORPORATED
    Inventors: Rabih Chrabieh, Samir S. Soliman
  • Publication number: 20080225982
    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: Application
    Filed: December 21, 2007
    Publication date: September 18, 2008
    Applicant: QUALCOMM INCORPORATED
    Inventors: Rabih Chrabieh, Koorosh Akhavan
  • Publication number: 20080219386
    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: Application
    Filed: September 11, 2007
    Publication date: September 11, 2008
    Applicant: QUALCOMM INCORPORATED
    Inventors: Rabih Chrabieh, Samir S. Soliman
  • Publication number: 20080219379
    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: Application
    Filed: May 30, 2007
    Publication date: September 11, 2008
    Inventor: Rabih Chrabieh
  • Publication number: 20080219339
    Abstract: A system and method are provided for supplying a frequency-smoothed communications training signal. The method generates a frequency-smoothed unbiased training signal in a quadrature modulation transmitter. The frequency-smoothed unbiased training signal includes a plurality of pilot signal products, where each pilot signal product includes complex plane information represented by a reference frequency subcarrier, multiplying complex plane information represented by mirror frequency subcarrier. The sum of the plurality of pilot signal products is equal to zero. The method supplies the frequency-smoothed unbiased training signal so that it may be transmitted within a single symbol period. System and methods are also provided for using a frequency-smoothed training signal in the calculation of a receiver channel estimate.
    Type: Application
    Filed: September 11, 2007
    Publication date: September 11, 2008
    Applicant: QUALCOMM INCORPORATED
    Inventors: Rabih Chrabieh, Samir S. Soliman
  • Publication number: 20080219338
    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: Application
    Filed: March 9, 2007
    Publication date: September 11, 2008
    Inventor: Rabih Chrabieh
  • Patent number: 7379740
    Abstract: This present invention concerns a method and a system for simulating and optimising the use of resources available in a zone of coverage of a mobile telephone network (RT), characterized, firstly, in that it is implemented by processing resources (10) of at least one resource optimization system (1) and, secondly, in that it includes the following stages determination (50), by an event management module (EM) of the optimization system (1), of a variation, called a disruption, of at least one packet (P) transmission (T) required within the network (RT), from at least one statistical distribution map (CR) held in storage resources (11) of the optimization system (1), and that consists of data representing data packet (P) transmissions (T), selection (52) of a set of cells determining a simulated zone (ZS), by a resource operating-resources control module (CL), and then use of a routing algorithm in order to determine a routing path (CP) in the simulated zone (ZS) and to successively optimize the resources of th
    Type: Grant
    Filed: November 14, 2006
    Date of Patent: May 27, 2008
    Assignee: Societe Francaise du Radiotelephone
    Inventors: Serge Barbosa Da Torre, Rabih Chrabieh, Imad Fattouch
  • Patent number: 7352774
    Abstract: According to an embodiment of the invention, a method and apparatus are described for data bit sequences. According to an embodiment of the invention, a header is inserted in a data burst. One or more high priority messages of a first type are optionally inserted in the data burst starting after the header. One or more messages of a second type are optionally inserted into the data burst starting at an end of the data burst. One or more low priority messages of the first type are optionally inserted in the data.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: April 1, 2008
    Assignee: Arraycomm, LLC
    Inventors: Christopher R. Uhlik, Douglas C. Dahlby, Rabih Chrabieh
  • Patent number: 7308268
    Abstract: A method and a system for simulating and optimising the operating resources available in a coverage area of a mobile telephone network implemented by processing resources of at least one resource optimisation system and, can include definition, by an event-management module of the optimisation system, of a variation, called a perturbation, of at least one transmission of packets required within the network, from at least one statistical distribution map, selection of a set of cells determining a simulated zone, by means of an operating-resource control module, and then use of a routing algorithm to determine a routing path in the simulated zone, and to successively optimise the resources of the servers, definition by the event-management module, of data that represent at least one parameter relating to the transmission of the packets within each of the cells in the simulated zone, from amongst at least parameters of time-multiplexing of the packet, code-multiplexing of the packet, and the power required.
    Type: Grant
    Filed: November 14, 2006
    Date of Patent: December 11, 2007
    Assignee: Societe Francaise du Radiotelephone
    Inventors: Serge Barbosa da Torre, Rabih Chrabieh, Imad Fattouch
  • Publication number: 20070149186
    Abstract: A method and a system for simulating and optimising the operating resources available in a coverage area of a mobile telephone network implemented by processing resources of at least one resource optimisation system and, can include definition, by an event-management module of the optimisation system, of a variation, called a perturbation, of at least one transmission of packets required within the network, from at least one statistical distribution map, selection of a set of cells determining a simulated zone, by means of an operating-resource control module, and then use of a routing algorithm to determine a routing path in the simulated zone, and to successively optimise the resources of the servers, definition by the event-management module, of data that represent at least one parameter relating to the transmission of the packets within each of the cells in the simulated zone, from amongst at least parameters of time-multiplexing of the packet, code-multiplexing of the packet, and the power required.
    Type: Application
    Filed: November 14, 2006
    Publication date: June 28, 2007
    Inventors: Serge Barbosa da Torre, Rabih Chrabieh, Imad Fattouch
  • Publication number: 20070127490
    Abstract: This present invention concerns a method and a system for simulating and optimising the use of resources available in a zone of coverage of a mobile telephone network (RT), characterised, firstly, in that it is implemented by processing resources (10) of at least one resource optimisation system (1) and, secondly, in that it includes the following stages determination (50), by an event management module (EM) of the optimisation system (1), of a variation, called a disruption, of at least one packet (P) transmission (T) required within the network (RT), from at least one statistical distribution map (CR) held in storage resources (11) of the optimisation system (1), and that consists of data representing data packet (P) transmissions (T), selection (52) of a set of cells determining a simulated zone (ZS), by a resource operating-resources control module (CL), and then use of a routing algorithm in order to determine a routing path (CP) in the simulated zone (ZS) and to successively optimise the resources of th
    Type: Application
    Filed: November 14, 2006
    Publication date: June 7, 2007
    Inventors: Serge BARBOSA DA TORRE, Rabih Chrabieh, Imad Fattouch
  • Publication number: 20060107268
    Abstract: A development and runtime framework for applications that execute in real-time operating systems. Application development is enhanced through simple instructions that allow a programmer to declare functions and sets of functions as tasks and supertasks, respectively, and manage the execution of functions, tasks and supertasks with priorities. A compiler or pre-processor provides tools for generating the code for tasks and supertasks, and the management code for managing execution. Function calls may be made directly to functions within supertasks via respective entrypoints, and the tasks are managed based on the functions being invoked. Within a supertask, a higher priority function may be runnable while a lower priority function of that supertask is suspended. A cookie is used to recognize when a register update for a supertask may be omitted, enabling more efficient context switching.
    Type: Application
    Filed: November 15, 2005
    Publication date: May 18, 2006
    Inventor: Rabih Chrabieh
  • Publication number: 20060031838
    Abstract: A development framework and runtime environment for applications that execute in real-time operating systems. Application development is enhanced by providing simple instructions that allow a programmer to declare any function as a function managed with priority. Compiler tools implement priority function and the management code for managing execution at runtime. At runtime, priority functions are managed based on their respective priority level. The priority function information is stored when execution is to be delayed.
    Type: Application
    Filed: August 5, 2005
    Publication date: February 9, 2006
    Inventor: Rabih Chrabieh