Patents by Inventor A. Roger Hammons

A. Roger Hammons 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: 7324482
    Abstract: General binary design criteria for PSK-modulated space-time codes are provided. For linear binary PSK (BPSK) codes and quadrature PSK (QPSK) codes, the rank (i.e., binary projections) of the unmodulated code words, as binary matrices over the binary field, is used as a design criterion. Fundamental code constructions for both quasi-static and time-varying channels are provided.
    Type: Grant
    Filed: January 13, 2004
    Date of Patent: January 29, 2008
    Assignee: The DIRECTV Group, Inc.
    Inventors: A. Roger Hammons, Jr., Hesham El Gamal
  • Patent number: 7315570
    Abstract: A communication system for transmitting encoded signals over a communication channel is disclosed. The system includes a transmitter, which has a source that outputs a message signal. The transmitter also includes an encoder that generates a code word in response to the message signal. The code word has a construction that defines a plurality of paths associated with an intersymbol interference (ISI) environment of the communication channel, wherein the code word achieves a diversity based upon the number of transmit antennas and the number of ISI paths. Further, the transmitter includes a modulator that modulates the code word for transmission over the communication channel, and multiple antennas that transmit the modulated code word over the communication channel. The system encompasses a receiver that receives the transmitted code word via a number of receive antennas.
    Type: Grant
    Filed: September 21, 2005
    Date of Patent: January 1, 2008
    Assignee: The DIRECTV Group, Inc.
    Inventors: Hesham El-Gamal, A. Roger Hammons, Jr.
  • Patent number: 7296212
    Abstract: Methods, apparatuses, and systems for encoding information symbols comprising loading information symbols into a data array with n(1) rows and n(2) columns, wherein each column has ki(1) information symbols, and wherein k(1) is an array that has at least two different values, encoding each column with a code Ci(1) from a family of nested codes C(1), wherein C(1) includes two different nested codes, and encoding each row with a code C(2).
    Type: Grant
    Filed: November 14, 2003
    Date of Patent: November 13, 2007
    Assignee: Broadwing Corporation
    Inventor: A. Roger Hammons, Jr.
  • Patent number: 7177365
    Abstract: A communication system for transmitting encoded signals over a communication channel is disclosed. The system includes a transmitter, which has a source that is configured to output a plurality of input signals. The transmitter also includes an encoder that is configured to generate a plurality of output signals in response to the plurality of the input signals to output a code word according to the plurality of output signals, wherein the code word has a predetermined algebraic construction for space-frequency coding based upon the communication channel being characterized as a frequency selective block fading channel. Further, the transmitter includes a modulator that is configured to modulate the code word for transmission over the communication channel, and a plurality of transmit antennas that configured to transmit the modulated code word over the communication channel.
    Type: Grant
    Filed: November 5, 2001
    Date of Patent: February 13, 2007
    Assignee: The DirecTV Group, Inc.
    Inventors: Hesham El-Gamal, Roger Hammons
  • Patent number: 7110464
    Abstract: A communication system for transmitting encoded signals over a communication channel is disclosed. The system includes a transmitter, which has a source that is configured to output a message signal, and an encoder that is configured to generate a code word in response to the message signal. The code word is based upon a stacking construction that is generalized for the communication channel. The communication channel is characterized as a multi-input multi-output (MIMO) block fading channel. The transmitter also includes a modulator that is configured to modulate the code word for transmission over the communication channel. Further, the transmitter includes a plurality of transmit antennas that are configured to transmit the modulated code word over the communication channel. The system also includes a receiver, which has a plurality of receive antennas. The receiver is configured to receive the transmitted code word via the plurality of receive antennas.
    Type: Grant
    Filed: October 6, 2005
    Date of Patent: September 19, 2006
    Assignee: The DirecTV Group, Inc.
    Inventors: Hesham El-Gamal, A. Roger Hammons, Jr.
  • Patent number: 7096404
    Abstract: A method of providing forward error correction for data services uses a parallel concatenated convolutional code which is a Turbo Code comprising a plurality of eight-state constituent encoders wherein a plurality of data block sizes are used in conjunction with said Turbo Code. A variation uses the method in a cellular radio system. Another variation uses the method in both forward and reverse likes of a cellular radio system.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: August 22, 2006
    Assignee: The DirectTV Group, Inc.
    Inventors: Mustafa Eroz, A. Roger Hammons, Jr.
  • Patent number: 7042956
    Abstract: A communication system for transmitting encoded signals over a communication channel is disclosed. The system includes a transmitter, which has a source that is configured to output a message signal, and an encoder that is configured to generate a code word in response to the message signal. The code word is based upon a stacking construction that is generalized for the communication channel. The communication channel is characterized as a multi-input multi-output (MIMO) block fading channel. The transmitter also includes a modulator that is configured to modulate the code word for transmission over the communication channel. Further, the transmitter includes a plurality of transmit antennas that are configured to transmit the modulated code word over the communication channel. The system also includes a receiver, which has a plurality of receive antennas. The receiver is configured to receive the transmitted code word via the plurality of receive antennas.
    Type: Grant
    Filed: November 5, 2001
    Date of Patent: May 9, 2006
    Inventors: Hesham El-Gamal, A. Roger Hammons, Jr.
  • Patent number: 7012967
    Abstract: Space-time codes for use with layered architectures with arbitrary numbers of antennas are provided such as rate k/n convolutional codes (e.g., rates higher than or equal to 1/n where n is the number of transmit antennas). Convolutional codes for layered space-time architectures are generated using matrices over the ring F[[D]] of formal power series in variable D.
    Type: Grant
    Filed: May 6, 2003
    Date of Patent: March 14, 2006
    Inventors: A. Roger Hammons, Jr., Hasham El Gamal
  • Patent number: 7010053
    Abstract: A communication system for transmitting encoded signals over a communication channel is disclosed. The system includes a transmitter, which has a source that outputs a message signal. The transmitter also includes an encoder that generates a code word in response to the message signal. The code word has a construction that defines a plurality of paths associated with an intersymbol interference (ISI) environment of the communication channel, wherein the code word achieves a diversity based upon the number of transmit antennas and the number of ISI paths. Further, the transmitter includes a modulator that modulates the code word for transmission over the communication channel, and multiple antennas that transmit the modulated code word over the communication channel. The system encompasses a receiver that receives the transmitted code word via a number of receive antennas.
    Type: Grant
    Filed: November 5, 2001
    Date of Patent: March 7, 2006
    Inventors: Hesham El-Gamal, A. Roger Hammons, Jr.
  • Patent number: 7010054
    Abstract: A communication system for transmitting encoded signals over a communication channel is disclosed. The system includes a transmitter, which has a source that is configured to output a message signal, and an encoder that is configured to generate a code word in response to the message signal. The code word has a construction that is based upon a single dimensional binary code and that specifies a space-time overlay having a predetermined constraint. The transmitter also includes a modulator that is configured to modulate the code word for transmission over the communication channel. Further, the transmitter includes multiple transmit antennas that are configured to transmit the modulated code word over the communication channel. The system also includes a receiver, which may include multiple receive antennas. The receiver is configured to receive the transmitted code word via the multiple receive antennas.
    Type: Grant
    Filed: November 7, 2001
    Date of Patent: March 7, 2006
    Assignee: The DIRECTV Group, Inc.
    Inventors: Hesham El-Gamal, A. Roger Hammons, Jr.
  • Patent number: 6925587
    Abstract: A method of interleaving blocks of indexed data of varying length is disclosed. The method includes the steps of: providing a set of basic Interleavers comprising a family of one or more permutations of the indexed data and having a variable length; selecting one of the basic Interleavers based upon a desired Interleaver length L; and adapting the selected basic Interleaver to produce an Interleaver having the desired Interleaver length L.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: August 2, 2005
    Assignee: Hughes Electronics Corporation
    Inventors: Mustafa Eroz, A. Roger Hammons, Jr., Feng-Wen Sun
  • Patent number: 6898248
    Abstract: A threaded space-time (TST) architecture in a multiple antenna wireless communication system uses the coded transmission in each layer of a transmission resource array as a space-time code. Each layer of a layer set is active during all available symbol transmission intervals, and each of the transmit antennas are used equally often, such that layers each transmit a symbol using a different antenna during each symbol transmission interval. A receiver is provided for multi-user reception using an iterative, soft-input/soft-output (SISO) multi-user detection algorithm based on minimum mean square error (MMSE) criterion, among other methods.
    Type: Grant
    Filed: July 11, 2000
    Date of Patent: May 24, 2005
    Assignee: Hughes Electronics Corporation
    Inventors: Hesham Elgamal, A. Roger Hammons, Jr.
  • Patent number: 6892342
    Abstract: A method and apparatus for Turbo encoding uses a set of rate-compatible Turbo Codes optimized at high code rates and derived from a universal constituent code. The Turbo Codes have rate-compatible puncturing patterns. The method comprises: encoding a signal at a first and second encoder using a best rate ½ constituent code universal with higher code rates, the first encoder and the second encoder each producing a respective plurality of parity bits for each information bit; puncturing the respective plurality of parity bits at each encoder with a higher rate best puncturing patterns; and puncturing the respective plurality of parity bits at each encoder with a lower rate best puncturing pattern. In a variation, the best rate ½ constituent code represents a concatenation of polynomials 1+D2+D3 (octal 13) and 1+D+D3 (octal 15), D a data bit. A Turbo Encoder is provided which has hardware to implement the method.
    Type: Grant
    Filed: January 3, 2002
    Date of Patent: May 10, 2005
    Assignee: Hughes Electronics Corporation
    Inventors: Mustafa Eroz, A. Roger Hammons, Jr.
  • Patent number: 6862706
    Abstract: A method of terminating two or more constituent encoders of a turbo encoder employing a turbo code, comprising the step of: generating tail input bits at each of two or more constituent encoders, including deriving the tail input bits from each of the two or more constituent encoders separately from a contents of shift registers within each of the two or more constituent encoders, after an encoding of information bits by the two or more constituent encoders; puncturing one or more tail output bits such that 1/R output tail bits are transmitted for each of a plurality of trellis branches, wherein R is a turbo code rate employed by the turbo encoder during an information bit transmission. In yet another variation, the step of puncturing the tail output bits further comprises the step of: transmitting, during trellis termination, the tail output bits, only if they are sent from an output branch of one of the two or more constituent encoders that are used during information bit transmission.
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: March 1, 2005
    Assignee: Hughes Electronics Corp.
    Inventors: Mustafa Eroz, A. Roger Hammons, Jr.
  • Patent number: 6859906
    Abstract: A system and method for decoding encoded data is provided. A parser receives and parses the encoded data into data streams, with each of the data streams including a portion of said encoded data. A decoder decodes the data streams to provide decoded data which includes soft decision data. The decoder performs an decoding iteration on each of the data streams to provide the decoded data, and performs such decoding iterations based on additional information. The system and method alternatively can be configured without a parser, and can employ at least one soft decoder module and another decoder module. The soft decoder module performs multiple decoding iterations on the encoded data to provide soft decision data and the other decoded module decodes the encoded data based on the soft decision data to provide hard decoded data representative of a decoded condition of said encoded data and/or soft decision data.
    Type: Grant
    Filed: February 12, 2001
    Date of Patent: February 22, 2005
    Assignee: Hughes Electronics Corporation
    Inventors: Roger Hammons, Bharath Venkartaramn, Mustafa Eroz
  • Patent number: 6857098
    Abstract: A method of providing forward error correction for data services uses a parallel concatenated convolutional code which is a Turbo Code comprising a plurality of eight-state constituent encoders wherein a plurality of data block sizes are used in conjunction with said Turbo Code. A variation uses the method in a cellular radio system. Another variation uses the method in both forward and reverse likes of a cellular radio system.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: February 15, 2005
    Assignee: Hughes Electronics Corporation
    Inventors: Mustafa Eroz, A. Roger Hammons, Jr.
  • Publication number: 20040146014
    Abstract: General binary design criteria for PSK-modulated space-time codes are provided. For linear binary PSK (BPSK) codes and quadrature PSK (QPSK) codes, the rank (i.e., binary projections) of the unmodulated code words, as binary matrices over the binary field, is used as a design criterion. Fundamental code constructions for both quasi-static and time-varying channels are provided.
    Type: Application
    Filed: January 13, 2004
    Publication date: July 29, 2004
    Applicant: HUGHES ELECTRONICS CORPORATION
    Inventors: A. Roger Hammons, Hesham El Gamal
  • Patent number: 6763493
    Abstract: An approach for performing computations that require processing of values in a forward sweep as well as a reverse sweep, such as the Maximum A Posteriori (MAP) algorithm, is disclosed. A first series of values are computed, in which only every fth value of the first series of values and associated normalization values are stored. The first series of values are indexed such that these first series of values are partitioned in time as blocks. The first series of values are recalculated on a per block basis, whereby a second series of values are calculated in response to these recalculated first series of values.
    Type: Grant
    Filed: September 21, 2001
    Date of Patent: July 13, 2004
    Assignee: The DIRECTV Group, Inc.
    Inventors: Bharath Venkataraman, Roger Hammons, Mustafa Eroz
  • Publication number: 20040120349
    Abstract: A system for transmitting data packets over an air interface includes a logic device and a transmitter. The logic device receives data packets from a user device and encodes the data packets using a turbo coding scheme. The logic device may then modulate the turbo coded data and forward the modulated data to a transmitter. The transmitter may then transmit the modulated data to a satellite over the air interface.
    Type: Application
    Filed: November 7, 2003
    Publication date: June 24, 2004
    Applicant: HUGHES ELECTRONICS
    Inventors: John Border, Martin Moseley, Enrique Laborde, Frank Kelly, Roger Hammons, Mustafa Eroz
  • Publication number: 20040123218
    Abstract: A method of providing forward error correction for data services uses a parallel concatenated convolutional code which is a Turbo Code comprising a plurality of eight-state constituent encoders wherein a plurality of data block sizes are used in conjunction with said Turbo Code. A variation uses the method in a cellular radio system. Another variation uses the method in both forward and reverse likes of a cellular radio system.
    Type: Application
    Filed: September 12, 2003
    Publication date: June 24, 2004
    Applicant: HUGHES ELECTRONICS CORPORATION
    Inventors: Mustafa Eroz, A. Roger Hammons