Patents by Inventor Ephraim Zehavi

Ephraim Zehavi 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: 5581575
    Abstract: A communication system for transmitting variable rate data is disclosed wherein redundancy is added to the variable rate data to provide repetition symbols. The repetition symbol data is transmitted with symbol energy scaled in accordance to the rate of the variable rate data when the variable rate data is greater than or equal to a nominal data rate. When the variable rate data is less than the nominal data rate, the symbol data is transmitted at nominal symbol energy and redundancy is removed by transmission gating of a proportion of the transmission symbol data determined in accordance with the rate of the variable rate data. Furthermore, a receiver for receiving the variable rate data is disclosed which uses the redundancy in the transmitted data symbol stream to make a corrected estimate of the transmitted symbol data.
    Type: Grant
    Filed: October 5, 1995
    Date of Patent: December 3, 1996
    Assignee: Qualcomm Incorporated
    Inventors: Ephraim Zehavi, Andrew J. Viterbi
  • Patent number: 5568483
    Abstract: A method and apparatus for arranging various types of data, and at various rates, into a uniquely structured format for transmission. Data for transmission formatting may be vocoder data or different types of non-vocoder data. The data organized into frames of a predetermined time duration for transmission. The data frames are organized, depending on the data, to be at one of several data rates. Vocoder data is provided at one of several data rates and is organized in the frame according to a predetermined format. Frames may be formatted with a sharing of vocoder data with non-vocoder data to be at a highest frame data rate. Different types of non-vocoder data may be organized so as to also be at the highest frame data rate. Additional control data may be provided within the data frames to support various aspects of the transmission and recovery upon reception.
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: October 22, 1996
    Assignee: Qualcomm Incorporated
    Inventors: Roberto Padovani, Edward G. Tiedemann, Jr., Joseph P. Odenwalder, Ephraim Zehavi, Charles E. Wheatley, III
  • Patent number: 5566206
    Abstract: A system for determining the rate at which data has been encoded in the receiver of a variable-rate communications system. The data is received in frames having a fixed number of symbols. Multiple copies of symbols fill the frame when data is encoded at less than the full rate. At an encoding rate of one fourth the full rate, for example, each symbol in the frame is repeated four times. The incoming symbols are provided to multiple paths for decoding. Each path decodes the symbols at one of the possible rates. Error metrics, which describe the quality of the decoded symbols, are extracted and provided to a processor. The error metrics may include Cyclic Redundancy Check (CRC) results, Yamamoto Quality Metrics, and Symbol Error Rates. The processor analyzes the error metrics and determines the most probable rate at which the incoming symbols were encoded.
    Type: Grant
    Filed: April 26, 1994
    Date of Patent: October 15, 1996
    Assignee: QUALCOMM Incorporated
    Inventors: Brian K. Butler, Roberto Padovani, Ephraim Zehavi
  • Patent number: 5471497
    Abstract: An improved system and method for communicating information at variable data rates over in-phase (I) and quadrature phase (Q) communication channels in a CDMA spread spectrum communication system is disclosed herein. In an exemplary implementation an input information signal is transmitted over either an I or Q communication channel using a direct sequence spread spectrum communication signal. The information signal is initially divided into first and second subsignals, which are respectively provided to first and second coset-encoding networks. The first coset-encoding combines the first subsignal with a first coset code, while the second coset-encoding network combines the second subsignal with a second coset code orthogonal to the first coset code. In this way the first and second coset-encoding networks are operative to produce first and second coset-encoded signals, respectively.
    Type: Grant
    Filed: November 1, 1993
    Date of Patent: November 28, 1995
    Inventor: Ephraim Zehavi
  • Patent number: 5469452
    Abstract: A decoder for decoding trellis coded data in which the received signal is assigned a sector value corresponding to the phase of the signal in accordance with a predetermined signal space sectorization format. A Viterbi decoder is used to reconstruct from the received signal an estimate of a data bit that was coded for transmission. This estimate is re-encoded and provided to a trellis output mapper along with the sector value. The trellis mapper in response to the input re-encoded estimate and sector value provides an estimate of an an uncoded data bit transmitted with the coded data bit.
    Type: Grant
    Filed: September 27, 1991
    Date of Patent: November 21, 1995
    Assignee: Qualcomm Incorporated
    Inventor: Ephraim Zehavi
  • Patent number: 5461639
    Abstract: The power control process of the present invention enables a mobile radiotelephone to continuously update the base station on the power output required. The base station sends a frame to the mobile at a particular rate. If the mobile received and decoded the frame correctly, it sets a power control bit in the next frame to be transmitted to the base station. Based on the error rate of the received power control bits, the base station determines whether to increase or decrease the transmit power.
    Type: Grant
    Filed: July 18, 1994
    Date of Patent: October 24, 1995
    Assignee: Qualcomm Incorporated
    Inventors: Charles E. Wheatley, III, Roberto Padovani, Ephraim Zehavi
  • Patent number: 5428631
    Abstract: A method and apparatus for trellis coding of input data as phase point data for M-ary modulation and transmission upon a communication channel and a method and apparatus for decoding same. The trellis encoding is accomplished by an input encoder for receiving and encoding according to a first encoding format a set of input user data bits to provide a set of symbols; a precoder for encoding according to a second encoding format a first symbol of the set symbols to provide a second symbol; an output encoder for encoding the second symbol according to a third encoding format to provide a third symbol wherein the third encoding format has an inverse transfer function relationship with the second encoding format, encoding the second symbol according to a fourth encoding format to provide a fourth symbol; and wherein remaining symbols of the set of symbols and the third and fourth symbols collectively represent phase point data.
    Type: Grant
    Filed: February 1, 1993
    Date of Patent: June 27, 1995
    Assignee: Qualcomm Incorporated
    Inventor: Ephraim Zehavi
  • Patent number: 5414728
    Abstract: An improved system and method for communicating information over in-phase (I) and quadrature phase (Q) communication channels in a spread spectrum communication system is disclosed herein. In an exemplary implementation, first and second information signals are respectively transmitted over the I and Q communication channels using direct sequence spread spectrum communication signals. In-phase pseudorandom noise (PN.sub.I) and quadrature phase pseudorandom noise (PN.sub.Q) signals of predetermined PN codes are used for spreading the first and second information signals, respectively. In particular, the PN.sub.I and PN.sub.Q signals are respectively combined with the first and second information signals and an orthogonal function signal to provide I-channel and Q-channel modulation signals. The I-channel and Q-channel modulation signals are used for modulating in-phase (I) and quadrature phase (Q) carrier signals for transmission to a receiver via the I and Q communication channels, respectively.
    Type: Grant
    Filed: November 1, 1993
    Date of Patent: May 9, 1995
    Assignee: Qualcomm Incorporated
    Inventor: Ephraim Zehavi
  • Patent number: 5383219
    Abstract: The power control process of the present invention enables a mobile radiotelephone to continuously update the base station on the power output required. The base station sends a frame to the mobile at a particular rate. If the mobile received and decoded the frame correctly, it sets a power control bit in the next frame to be transmitted to the base station. Based on the error rate of the received power control bits, the base station determines whether to increase or decrease the transmit power.
    Type: Grant
    Filed: November 22, 1993
    Date of Patent: January 17, 1995
    Assignee: Qualcomm Incorporated
    Inventors: Charles E. Wheatley, III, Roberto Padovani, Ephraim Zehavi