Patents by Inventor Dariush Divsalar
Dariush Divsalar 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).
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Patent number: 8689083Abstract: Digital communication coding methods resulting in rate-compatible low density parity-check (LDPC) codes built from protographs. Described digital coding methods start with a desired code rate and a selection of the numbers of variable nodes and check nodes to be used in the protograph. Constraints are set to satisfy a linear minimum distance growth property for the protograph. All possible edges in the graph are searched for the minimum iterative decoding threshold and the protograph with the lowest iterative decoding threshold is selected. Protographs designed in this manner are used in decode and forward relay channels.Type: GrantFiled: June 10, 2011Date of Patent: April 1, 2014Assignees: California Institute of Technology, Board of Regents, The University of Texas SystemInventors: Thuy V. Nguyen, Aria Nosratinia, Dariush Divsalar
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Publication number: 20130139024Abstract: Digital communication coding methods for designing protograph-based BICM that is general and applies to any modulation. The general coding framework can support not only multiple rates but also adaptive modulation. The method is a two stage lifting approach. In the first stage, an original protograph is lifted to a slightly larger intermediate protograph. The intermediate protograph is then lifted via a circulant matrix to the expected codeword length to form a protograph-based LDPC code.Type: ApplicationFiled: November 29, 2011Publication date: May 30, 2013Inventors: Thuy V. Nguyen, Aria Nosratinia, Dariush Divsalar
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Patent number: 8358723Abstract: A method, radio receiver, and system to autonomously receive and decode a plurality of signals having a variety of signal types without a priori knowledge of the defining characteristics of the signals is disclosed. The radio receiver is capable of receiving a signal of an unknown signal type and, by estimating one or more defining characteristics of the signal, determine the type of signal. The estimated defining characteristic(s) is/are utilized to enable the receiver to determine other defining characteristics. This in turn, enables the receiver, through multiple iterations, to make a maximum-likelihood (ML) estimate for each of the defining characteristics. After the type of signal is determined by its defining characteristics, the receiver selects an appropriate decoder from a plurality of decoders to decode the signal.Type: GrantFiled: November 10, 2006Date of Patent: January 22, 2013Assignee: The United States of America as Represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Jon Hamkins, Marvin K. Simon, Dariush Divsalar, Samuel J. Dolinar, Andre Tkacenko
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Publication number: 20120275546Abstract: Multiple symbol noncoherent soft output detectors in accordance with embodiments of the invention are disclosed. In a number of embodiments, the multiple symbol noncoherent soft output detector uses soft metrics based on the Log Likelihood Ratio (LLR) of each symbol to provide information concerning the reliability of each detected symbol. One embodiment of the invention includes a receiver configured to receive and sample a phase modulated input signal, and a multiple symbol noncoherent soft output detector configured to receive the sampled input signal and to generate a soft metric indicative of the reliability of a detected symbol based upon observations over multiple symbols.Type: ApplicationFiled: March 7, 2012Publication date: November 1, 2012Applicant: Mojix, Inc.Inventor: Dariush Divsalar
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Patent number: 8239746Abstract: Digital communication coding methods are shown, which generate certain types of low-density parity-check (LDPC) codes built from protographs. A first method creates protographs having the linear minimum distance property and comprising at least one variable node with degree less than 3. A second method creates families of protographs of different rates, all structurally identical for all rates except for a rate-dependent designation of certain variable nodes as transmitted or non-transmitted. A third method creates families of protographs of different rates, all structurally identical for all rates except for a rate-dependent designation of the status of certain variable nodes as non-transmitted or set to zero. LDPC codes built from the protographs created by these methods can simultaneously have low error floors and low iterative decoding thresholds.Type: GrantFiled: December 30, 2011Date of Patent: August 7, 2012Assignee: California Institute of TechnologyInventors: Dariush Divsalar, Samuel J. Dolinar, Jr., Christopher R. Jones
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Publication number: 20120131409Abstract: Digital communication coding methods are shown, which generate certain types of low-density parity-check (LDPC) codes built from protographs. A first method creates protographs having the linear minimum distance property and comprising at least one variable node with degree less than 3. A second method creates families of protographs of different rates, all structurally identical for all rates except for a rate-dependent designation of certain variable nodes as transmitted or non-transmitted. A third method creates families of protographs of different rates, all structurally identical for all rates except for a rate-dependent designation of the status of certain variable nodes as non-transmitted or set to zero. LDPC codes built from the protographs created by these methods can simultaneously have low error floors and low iterative decoding thresholds.Type: ApplicationFiled: December 30, 2011Publication date: May 24, 2012Applicant: CALIFORNIA INSTITUTE OF TECHNOLOGYInventors: Dariush DIVSALAR, Samuel J. DOLINAR, JR., Christopher R. JONES
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Patent number: 8117523Abstract: Digital communication coding methods are shown, which generate certain types of low-density parity-check (LDPC) codes built from protographs. A first method creates protographs having the linear minimum distance property and comprising at least one variable node with degree less than 3. A second method creates families of protographs of different rates, all having the linear minimum distance property, and structurally identical for all rates except for a rate-dependent designation of certain variable nodes as transmitted or non-transmitted. A third method creates families of protographs of different rates, all having the linear minimum distance property, and structurally identical for all rates except for a rate-dependent designation of the status of certain variable nodes as non-transmitted or set to zero.Type: GrantFiled: May 22, 2008Date of Patent: February 14, 2012Assignee: California Institute of TechnologyInventors: Dariush Divsalar, Samuel J Dolinar, Jr., Christopher R. Jones
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Patent number: 8086943Abstract: Serial concatenated trellis coded modulation (SCTCM) includes an outer coder, an interleaver, a recursive inner coder and a mapping element. The outer coder receives data to be coded and produces outer coded data. The interleaver permutes the outer coded data to produce interleaved data. The recursive inner coder codes the interleaved data to produce inner coded data. The mapping element maps the inner coded data to a symbol. The recursive inner coder has a structure which facilitates iterative decoding of the symbols at a decoder system. The recursive inner coder and the mapping element are selected to maximize the effective free Euclidean distance of a trellis coded modulator formed from the recursive inner coder and the mapping element. The decoder system includes a demodulation unit, an inner SISO (soft-input soft-output) decoder, a deinterleaver, an outer SISO decoder, and an interleaver.Type: GrantFiled: August 2, 2010Date of Patent: December 27, 2011Assignee: California Institute of TechnologyInventors: Dariush Divsalar, Samuel J. Dolinar, Fabrizio Pollara
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Publication number: 20110307756Abstract: Digital communication coding methods resulting in rate-compatible low density parity-check (LDPC) codes built from protographs. Described digital coding methods start with a desired code rate and a selection of the numbers of variable nodes and check nodes to be used in the protograph. Constraints may be set to satisfy a linear minimum distance growth property for the protograph. All possible edges in the graph are searched for the minimum iterative decoding threshold and the protograph with the lowest iterative decoding threshold is selected. Protographs designed in this manner may be used in decode and forward relay channels.Type: ApplicationFiled: June 10, 2011Publication date: December 15, 2011Inventors: Thuy V. NGUYEN, Aria NOSRATINIA, Dariush DIVSALAR
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Publication number: 20100299581Abstract: Serial concatenated trellis coded modulation (SCTCM) includes an outer coder, an interleaver, a recursive inner coder and a mapping element. The outer coder receives data to be coded and produces outer coded data. The interleaver permutes the outer coded data to produce interleaved data. The recursive inner coder codes the interleaved data to produce inner coded data. The mapping element maps the inner coded data to a symbol. The recursive inner coder has a structure which facilitates iterative decoding of the symbols at a decoder system. The recursive inner coder and the mapping element are selected to maximize the effective free Euclidean distance of a trellis coded modulator formed from the recursive inner coder and the mapping element. The decoder system includes a demodulation unit, an inner SISO (soft-input soft-output) decoder, a deinterleaver, an outer SISO decoder, and an interleaver.Type: ApplicationFiled: August 2, 2010Publication date: November 25, 2010Inventors: Dariush Divsalar, Sam Dolinar, Fabrizio Pollara
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Patent number: 7770093Abstract: Serial concatenated trellis coded modulation (SCTCM) includes an outer coder, an interleaver, a recursive inner coder and a mapping element. The outer coder receives data to be coded and produces outer coded data. The interleaver permutes the outer coded data to produce interleaved data. The recursive inner coder codes the interleaved data to produce inner coded data. The mapping element maps the inner coded data to a symbol. The recursive inner coder has a structure which facilitates iterative decoding of the symbols at a decoder system. The recursive inner coder and the mapping element are selected to maximize the effective free Euclidean distance of a trellis coded modulator formed from the recursive inner coder and the mapping element. The decoder system includes a demodulation unit, an inner SISO (soft-input soft-output) decoder, a deinterleaver, an outer SISO decoder, and an interleaver.Type: GrantFiled: August 31, 2006Date of Patent: August 3, 2010Inventors: Dariush Divsalar, Samuel J. Dolinar, Fabrizio Pollara
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Patent number: 7716552Abstract: A turbo-like code is formed by repeating the signal, coding it, and interleaving it. A serial concatenated coder is formed of an inner coder and an outer coder separated by an interleaver. The outer coder is a coder which has rate greater than one e.g. a repetition coder. The interleaver rearranges the bits. An outer coder is a rate one coder.Type: GrantFiled: May 5, 2006Date of Patent: May 11, 2010Assignee: California Institute of TechnologyInventors: Dariush Divsalar, Robert J. McEliece, Hui Jin, Fabrizio Pollara
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Patent number: 7693235Abstract: A concatenated coding scheme, using an outer coder, interleaver, and the inner coder inherent in an FQPSK signal to form a coded FQPSK signal. The inner coder is modified to enable interative decoding of the outer code.Type: GrantFiled: August 31, 2006Date of Patent: April 6, 2010Assignee: California Institute of TechnologyInventors: Marvin K. Simon, Dariush Divsalar
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Patent number: 7499490Abstract: Methods and apparatus to encode message input symbols in accordance with an accumulate-repeat-accumulate code with repetition three or four are disclosed. Block circulant matrices are used. A first method and apparatus make use of the block-circulant structure of the parity check matrix. A second method and apparatus use block-circulant generator matrices.Type: GrantFiled: June 24, 2005Date of Patent: March 3, 2009Assignees: California Institute of Technology, The Regents of the University of CaliforniaInventors: Dariush Divsalar, Aliazam Abbasfar, Christopher R. Jones, Samuel J. Dolinar, Jeremy C. Thorpe, Kenneth S. Andrews, Kung Yao
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Publication number: 20080294969Abstract: Digital communication coding methods are shown, which generate certain types of low-density parity-check (LDPC) codes built from protographs. A first method creates protographs having the linear minimum distance property and comprising at least one variable node with degree less than 3. A second method creates families of protographs of different rates, all having the linear minimum distance property, and structurally identical for all rates except for a rate-dependent designation of certain variable nodes as transmitted or non-transmitted. A third method creates families of protographs of different rates, all having the linear minimum distance property, and structurally identical for all rates except for a rate-dependent designation of the status of certain variable nodes as non-transmitted or set to zero.Type: ApplicationFiled: May 22, 2008Publication date: November 27, 2008Inventors: Dariush DIVSALAR, Samuel J. DOLINAR, JR., Christopher R. JONES
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Patent number: 7343539Abstract: An apparatus and method for encoding low-density parity check codes. Together with a repeater, an interleaver and an accumulator, the apparatus comprises a precoder, thus forming accumulate-repeat-accumulate (ARA codes). Protographs representing various types of ARA codes, including AR3A, AR4A and ARJA codes, are described. High performance is obtained when compared to the performance of current repeat-accumulate (RA) or irregular-repeat-accumulate (IRA) codes.Type: GrantFiled: June 24, 2005Date of Patent: March 11, 2008Assignee: The United States of America as represented by the United States National Aeronautics and Space AdministrationInventors: Dariush Divsalar, Aliazam Abbasfar, Christopher R. Jones, Samuel J. Dolinar, Jeremy C. Thorpe, Kenneth S. Andrews, Kung Yao
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Patent number: 7333571Abstract: A concatenated coding scheme, using an outer coder, interleaver, and the inner coder inherent in an FQPSK signal to form a coded FQPSK signal. The inner coder is modified to enable interactive decoding of the outer code.Type: GrantFiled: April 23, 2002Date of Patent: February 19, 2008Assignee: California Institute of TechnologyInventors: Marvin K. Simon, Dariush Divsalar
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Patent number: 7292654Abstract: A concatenated coding scheme, using an outer coder, interleaver, and the inner coder inherent in an FQPSK signal to form a coded FQPSK signal. The inner coder is modified to enable interative decoding of the outer code.Type: GrantFiled: August 31, 2006Date of Patent: November 6, 2007Assignee: California Institue of TechnologyInventors: Marvin K. Simon, Dariush Divsalar
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Patent number: 7243294Abstract: A coding system uses a serially concatenated coder driving an interleaver, which drives a trellis coder. This combination, while similar to a turbo coder, produces certain different characteristics.Type: GrantFiled: January 11, 2001Date of Patent: July 10, 2007Assignee: California Institute of TechnologyInventors: Dariush Divsalar, Sam Dolinar, Fabrizio Pollara
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Publication number: 20070127595Abstract: A concatenated coding scheme, using an outer coder, interleaver, and the inner coder inherent in an FQPSK signal to form a coded FQPSK signal. The inner coder is modified to enable interative decoding of the outer code.Type: ApplicationFiled: August 31, 2006Publication date: June 7, 2007Inventors: Marvin Simon, Dariush Divsalar