Patents by Inventor Brian A. Cameron

Brian A. Cameron 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).

  • Publication number: 20120192029
    Abstract: LDPC (Low Density Parity Check) codes with corresponding parity check matrices selectively constructed with CSI (Cyclic Shifted Identity) and null sub-matrices. An LDPC matrix corresponding to an LDPC code is employed within a communication device to encode and/or decode coded signals for use in any of a number of communication systems. The LDPC matrix is composed of a number of sub-matrices and may be partitioned into a left hand side matrix and a right hand side matrix. The right hand side matrix may include two sub-matrix diagonals therein that are composed entirely of CSI (Cyclic Shifted Identity) sub-matrices; one of these two sub-matrix diagonals is located on the center sub-matrix diagonal and the other is located just to the left thereof. All other sub-matrices of the right hand side matrix may be null sub-matrices (i.e., all elements therein are values of zero “0”).
    Type: Application
    Filed: March 19, 2012
    Publication date: July 26, 2012
    Applicant: BROADCOM CORPORATION
    Inventors: Ba-Zhong Shen, Hau Thien Tran, Tak K. Lee, Kelly Brian Cameron
  • Patent number: 8230298
    Abstract: Overlapping sub-matrix based LDPC (Low Density Parity Check) decoder. Novel decoding approach is presented, by which, updated bit edge messages corresponding to a sub-matrix of an LDPC matrix are immediately employed for updating of the check edge messages corresponding to that sub-matrix without requiring storing the bit edge messages; also updated check edge messages corresponding to a sub-matrix of the LDPC matrix are immediately employed for updating of the bit edge messages corresponding to that sub-matrix without requiring storing the check edge messages. Using this approach, twice as many decoding iterations can be performed in a given time period when compared to a system that performs updating of all check edge messages for the entire LDPC matrix, then updating of all bit edge messages for the entire LDPC matrix, and so on. When performing this overlapping approach in conjunction with min-sum processing, significant memory savings can also be achieved.
    Type: Grant
    Filed: January 1, 2010
    Date of Patent: July 24, 2012
    Assignee: Broadcom Corporation
    Inventors: Hau Thien Tran, Kelly Brian Cameron, Ba-Zhong Shen, Tak K. Lee
  • Patent number: 8229039
    Abstract: Flexible rate matching. No constraints or restrictions are placed on a sending communication device when effectuating rate matching. The receiving communication device is able to accommodate received transmissions of essentially any size (e.g., up to an entire turbo codeword that includes all systematic bits and all parity bits). The receiving communication device employs a relatively small-sized memory to ensure a lower cost, smaller sized communication device (e.g., handset or user equipment such as a personal wireless communication device). Moreover, incremental redundancy is achieved in which successive transmissions need not include repeated information therein (e.g., a second transmission need not include any repeated information from a first transmission). Only when reaching an end of a block of bits or codeword to be transmitted, and when wrap around at the end of such block of bits or codeword occurs, would any repeat of bits be incurred within a later transmission.
    Type: Grant
    Filed: November 18, 2008
    Date of Patent: July 24, 2012
    Assignee: Broadcom Corporation
    Inventors: Ba-Zhong Shen, Sirikiat Lek Ariyavisitakul, Mark Kent, Tak K. Lee, Kelly Brian Cameron
  • Patent number: 8176380
    Abstract: Algebraic method to construct LDPC (Low Density Parity Check) codes with parity check matrix having CSI (Cyclic Shifted Identity) sub-matrices. A novel approach is presented by which identity sub-matrices undergo cyclic shifting, thereby generating CSI sub-matrices that are arranged forming a parity check matrix of an LDPC code. The parity check matrix of the LDPC code may correspond to a regular LDPC code, or the parity check matrix of the LDPC code may undergo further modification to transform it to that of an irregular LDPC code. The parity check matrix of the LDPC code may be partitioned into 2 sub-matrices such that one of these 2 sub-matrices is transformed to be a block dual diagonal matrix; the other of these 2 sub-matrices may be modified using a variety of means, including the density evolution approach, to ensure the desired bit and check degrees of the irregular LDPC code.
    Type: Grant
    Filed: November 6, 2009
    Date of Patent: May 8, 2012
    Assignee: Broadcom Corporation
    Inventors: Ba-Zhong Shen, Joseph Paul Lauer, Christopher J. Hansen, Kelly Brian Cameron
  • Patent number: 8145987
    Abstract: LDPC (Low Density Parity Check) codes with corresponding parity check matrices selectively constructed with CSI (Cyclic Shifted Identity) and null sub-matrices. An LDPC matrix corresponding to an LDPC code is employed within a communication device to encode and/or decode coded signals for use in any of a number of communication systems. The LDPC matrix is composed of a number of sub-matrices and may be partitioned into a left hand side matrix and a right hand side matrix. The right hand side matrix may include two sub-matrix diagonals therein that are composed entirely of CSI (Cyclic Shifted Identity) sub-matrices; one of these two sub-matrix diagonals is located on the center sub-matrix diagonal and the other is located just to the left thereof. All other sub-matrices of the right hand side matrix may be null sub-matrices (i.e., all elements therein are values of zero “0”).
    Type: Grant
    Filed: January 13, 2011
    Date of Patent: March 27, 2012
    Assignee: Broadcom Corporation
    Inventors: Ba-Zhong Shen, Hau Thien Tran, Tak K. Lee, Kelly Brian Cameron
  • Publication number: 20120027683
    Abstract: T cell receptors (TCRs) having the property of binding to a murine insulin-derived peptide, LYLVCGERG (SEQ ID NO:62), presented by the murine H-2Kd complex (LYLVCGERG-H-2Kd). The TCRs comprise at least one TCR ? chain variable domain and/or at least one TCR ? chain variable domain and have a KD for the LYLVCGERG-H-2Kd complex of less than or equal to 1 ?M and/or have an off-rate (koff) for the LYLVCGERG-H-2Kd complex of 0.5 S?1 or slower, and use of such TCRs as research tools.
    Type: Application
    Filed: September 2, 2009
    Publication date: February 2, 2012
    Inventors: Neill MacKenzie, Bent Jakobsen, Daniel Williams, Brian Cameron
  • Publication number: 20120014364
    Abstract: A wireless local area network (WLAN) transmitter includes a baseband processing module and a plurality of radio frequency (RF) transmitters. The processing module selects one of a plurality of modes of operation based on a mode selection signal. The processing module determines a number of transmit streams based on the mode selection signal. The processing of the data further continues by converting encoded data into streams of symbols in accordance with the number of transmit streams and the mode selection signal. A number of the plurality of RF transmitters are enabled based on the mode selection signal to convert a corresponding one of the streams of symbols into a corresponding RF signal such that a corresponding number of RF signals is produced.
    Type: Application
    Filed: September 26, 2011
    Publication date: January 19, 2012
    Applicant: BROADCOM CORPORATION
    Inventors: Christopher J. Hansen, Jason A. Trachewsky, Nambirajan Seshadri, Kelly Brian Cameron, Hau Thien Tran, Ba-Zhong Shen
  • Patent number: 8086930
    Abstract: Fixed-spacing parity insertion for FEC (Forward Error Correction) codewords. Fixed spacing is employed to intersperse parity bits among information bits when generating a codeword. According to this fixed spacing, a same number of information bits is placed between each of the parity bits within the codeword. If desired, the order of the parity bits may be changed before they are placed into the codeword. Moreover, the order of the information bits may also be modified before they are placed into the codeword. The FEC encoding employed to generate the parity bits from the information bits can be any of a variety of codes include Reed-Solomon (RS) code, LDPC (Low Density Parity Check) code, turbo code, turbo trellis coded modulation (TTCM), or some other code providing FEC capabilities.
    Type: Grant
    Filed: January 29, 2008
    Date of Patent: December 27, 2011
    Assignee: Broadcom Corporation
    Inventors: Tak K. Lee, Ba-Zhong Shen, Hau Thien Tran, Kelly Brian Cameron
  • Patent number: 8059740
    Abstract: A wireless local area network (WLAN) transmitter includes a baseband processing module and a plurality of radio frequency (RF) transmitters. The baseband processing module is operably coupled to process data by scrambling the data in accordance with a pseudo random sequence to produce scrambled data. The processing of the data continues by selecting one of a plurality of encoding modes based on a mode selection signal. The processing of the data continues by encoding the scrambled data in accordance with the one of the plurality of encoding modes to produce encoded data. The processing of the data continues by determining a number of transmit streams based on the mode selection signal. The processing of the data further continues by converting the encoded data into streams of symbols in accordance with the number of transmit streams and the mode selection signal.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: November 15, 2011
    Assignee: Broadcom Corporation
    Inventors: Christopher J. Hansen, Jason A. Trachewsky, Nambirajan Seshadri, Kelly Brian Cameron, Hau Thien Tran, Ba-Zhong Shen
  • Publication number: 20110258518
    Abstract: Variable modulation within combined LDPC (Low Density Parity Check) coding and modulation coding systems. A novel approach is presented for variable modulation encoding of LDPC coded symbols. In addition, LDPC encoding, that generates an LDPC variable code rate signal, may also be performed as well. The encoding can generate an LDPC variable code rate and/or modulation signal whose code rate and/or modulation may vary as frequently as on a symbol by symbol basis. Some embodiments employ a common constellation shape for all of the symbols of the signal sequence, yet individual symbols may be mapped according different mappings of the commonly shaped constellation; such an embodiment may be viewed as generating a LDPC variable mapped signal. In general, any one or more of the code rate, constellation shape, or mapping of the individual symbols of a signal sequence may vary as frequently as on a symbol by symbol basis.
    Type: Application
    Filed: May 26, 2011
    Publication date: October 20, 2011
    Applicant: BROADCOM CORPORATION
    Inventors: Ba-Zhong Shen, Hau Thien Tran, Kelly Brian Cameron
  • Patent number: 8010246
    Abstract: The present locomotive brake control system includes a vacuum relay valve responsive to air brake apply and release signals on the air brake pipe to provide vacuum brake apply and release signals on a vacuum brake pipe. A locomotive brake controller is responsive to the brake apply and release signals on the air brake pipe to control the brake cylinder to apply and release the locomotive brakes in an air mode, and is responsive to the brake apply and release signals on the vacuum brake pipe sensed by a transducer to control the brake cylinder to apply and release the locomotive brakes in a vacuum mode.
    Type: Grant
    Filed: February 14, 2008
    Date of Patent: August 30, 2011
    Assignee: New York Air Brake Corporation
    Inventors: Robert Carter, Brian Cameron, Vincent S. Guarrera, Jr., John Reynolds, Jon Marra
  • Patent number: 7975202
    Abstract: Variable modulation with LDPC (Low Density Parity Check) coding provides for generation of LDPC coded symbols having different respective code rates and/or modulations. In addition, appropriate LDPC encoding, that generates an LDPC variable code rate signal, may also be performed as well. The encoding can generate an LDPC variable code rate and/or modulation signal whose code rate and/or modulation may vary as frequently as on a symbol by symbol basis. Some embodiments employ a common constellation shape for all of the symbols of the signal sequence, yet individual symbols may be mapped according different mappings of the commonly shaped constellation; such an embodiment may be viewed as generating a LDPC variable mapped signal. In general, any one or more of the code rate, constellation shape, and/or mapping of the individual symbols of a signal sequence may vary as frequently as on a symbol by symbol basis.
    Type: Grant
    Filed: October 3, 2006
    Date of Patent: July 5, 2011
    Assignee: Broadcom Corporation
    Inventors: Ba-Zhong Shen, Hau Thien Tran, Kelly Brian Cameron
  • Patent number: 7958428
    Abstract: LDPC (Low Density Parity Check) coded signal decoding using parallel and simultaneous bit node and check node processing. This novel approach to decoding of LDPC coded signals may be described as being LDPC bit-check parallel decoding. In some alternative embodiment, the approach to decoding LDPC coded signals may be modified to LDPC symbol-check parallel decoding or LDPC hybrid-check parallel decoding. A novel approach is presented by which the edge messages with respect to the bit nodes and the edge messages with respect to the check nodes may be updated simultaneously and in parallel to one another. Appropriately constructed executing orders direct the sequence of simultaneous operation of updating the edge messages at both nodes types (e.g., edge and check). For various types of LDPC coded signals, including parallel-block LDPC coded signals, this approach can perform decoding processing in almost half of the time as provided by previous decoding approaches.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: June 7, 2011
    Assignee: Broadcom Corporation
    Inventors: Ba-Zhong Shen, Hau Thien Tran, Kelly Brian Cameron
  • Publication number: 20110110353
    Abstract: A wireless local area network (WLAN) transmitter includes a MAC module, a PLCP module, and a PMD module. The Medium Access Control (MAC) module is operably coupled to convert a MAC Service Data Unit (MSDU) into a MAC Protocol Data Unit (MPDU) in accordance with a WLAN protocol. The Physical Layer Convergence Procedure (PLCP) Module is operably coupled to convert the MPDU into a PLCP Protocol Data Unit (PPDU) in accordance with the WLAN protocol. The Physical Medium Dependent (PMD) module is operably coupled to convert the PPDU into a plurality of radio frequency (RF) signals in accordance with one of a plurality of operating modes of the WLAN protocol, wherein the plurality of operating modes includes multiple input and multiple output combinations.
    Type: Application
    Filed: January 13, 2011
    Publication date: May 12, 2011
    Applicant: BROADCOM CORPORATION
    Inventors: Christopher J. Hansen, Jason A. Trachewsky, Nambirajan Seshadri, Kelly Brian Cameron, Hau Thien Tran, Ba-Zhong Shen
  • Publication number: 20110107175
    Abstract: LDPC (Low Density Parity Check) codes with corresponding parity check matrices selectively constructed with CSI (Cyclic Shifted Identity) and null sub-matrices. An LDPC matrix corresponding to an LDPC code is employed within a communication device to encode and/or decode coded signals for use in any of a number of communication systems. The LDPC matrix is composed of a number of sub-matrices and may be partitioned into a left hand side matrix and a right hand side matrix. The right hand side matrix may include two sub-matrix diagonals therein that are composed entirely of CSI (Cyclic Shifted Identity) sub-matrices; one of these two sub-matrix diagonals is located on the center sub-matrix diagonal and the other is located just to the left thereof. All other sub-matrices of the right hand side matrix may be null sub-matrices (i.e., all elements therein are values of zero “0”).
    Type: Application
    Filed: January 13, 2011
    Publication date: May 5, 2011
    Applicant: BROADCOM CORPORATION
    Inventors: Ba-Zhong Shen, Hau Thien Tran, Tak K. Lee, Kelly Brian Cameron
  • Publication number: 20110072336
    Abstract: LDPC (Low Density Parity Check) coded modulation symbol decoding. Symbol decoding is supported by appropriately modifying an LDPC tripartite graph to eliminate the bit nodes thereby generating an LDPC bipartite graph (such that symbol nodes are appropriately mapped directly to check nodes thereby obviating the bit nodes). The edges that communicatively couple the symbol nodes to the check nodes are labeled appropriately to support symbol decoding of the LDPC coded modulation signal. The iterative decoding processing may involve updating the check nodes as well as estimating the symbol sequence and updating the symbol nodes. In some embodiments, an alternative hybrid decoding approach may be performed such that a combination of bit level and symbol level decoding is performed. This LDPC symbol decoding out-performs bit decoding only. In addition, it provides comparable or better performance of bit decoding involving iterative updating of the associated metrics.
    Type: Application
    Filed: November 30, 2010
    Publication date: March 24, 2011
    Applicant: BROADCOM CORPORATION
    Inventors: Ba-Zhong Shen, Hau Thien Tran, Kelly Brian Cameron
  • Patent number: 7900127
    Abstract: LDPC (Low Density Parity Check) codes with corresponding parity check matrices selectively constructed with CSI (Cyclic Shifted Identity) and null sub-matrices. An LDPC matrix corresponding to an LDPC code is employed within a communication device to encode and/or decode coded signals for use in any of a number of communication systems. The LDPC matrix is composed of a number of sub-matrices and may be partitioned into a left hand side matrix and a right hand side matrix. The right hand side matrix may include two sub-matrix diagonals therein that are composed entirely of CSI (Cyclic Shifted Identity) sub-matrices; one of these two sub-matrix diagonals is located on the center sub-matrix diagonal and the other is located just to the left thereof. All other sub-matrices of the right hand side matrix may be null sub-matrices (i.e., all elements therein are values of zero “0”).
    Type: Grant
    Filed: July 31, 2009
    Date of Patent: March 1, 2011
    Assignee: Broadcom Corporation
    Inventors: Ba-Zhong Shen, Hau Thien Tran, Tak K. Lee, Kelly Brian Cameron
  • Patent number: 7873022
    Abstract: A wireless local area network (WLAN) transmitter includes a MAC module, a PLCP module, and a PMD module. The Medium Access Control (MAC) module is operably coupled to convert a MAC Service Data Unit (MSDU) into a MAC Protocol Data Unit (MPDU) in accordance with a WLAN protocol. The Physical Layer Convergence Procedure (PLCP) Module is operably coupled to convert the MPDU into a PLCP Protocol Data Unit (PPDU) in accordance with the WLAN protocol. The Physical Medium Dependent (PMD) module is operably coupled to convert the PPDU into a plurality of radio frequency (RF) signals in accordance with one of a plurality of operating modes of the WLAN protocol, wherein the plurality of operating modes includes multiple input and multiple output combinations.
    Type: Grant
    Filed: September 3, 2004
    Date of Patent: January 18, 2011
    Assignee: Broadcom Corporation
    Inventors: Christopher J. Hansen, Jason A. Trachewsky, Nambirajan Seshadri, Kelly Brian Cameron, Hau Thien Tran, Ba-Zhong Shen
  • Patent number: 7849389
    Abstract: LDPC (Low Density Parity Check) coded modulation symbol decoding. Symbol decoding is supported by appropriately modifying an LDPC tripartite graph to eliminate the bit nodes thereby generating an LDPC bipartite graph (such that symbol nodes are appropriately mapped directly to check nodes thereby obviating the bit nodes). The edges that communicatively couple the symbol nodes to the check nodes are labeled appropriately to support symbol decoding of the LDPC coded modulation signal. The iterative decoding processing may involve updating the check nodes as well as estimating the symbol sequence and updating the symbol nodes. In some embodiments, an alternative hybrid decoding approach may be performed such that a combination of bit level and symbol level decoding is performed. This LDPC symbol decoding out-performs bit decoding only. In addition, it provides comparable or better performance of bit decoding involving iterative updating of the associated metrics.
    Type: Grant
    Filed: October 5, 2006
    Date of Patent: December 7, 2010
    Assignee: Broadcom Corporation
    Inventors: Ba-Zhong Shen, Hau Thien Tran, Kelly Brian Cameron
  • Publication number: 20100220804
    Abstract: A method for asymmetrical MIMO wireless communication begins by determining a number of transmission antennas for the asymmetrical MIMO wireless communication. The method continues by determining a number of reception antennas for the asymmetrical MIMO wireless communication. The method continues by, when the number of transmission antennas exceeds the number of reception antennas, using spatial time block coding for the asymmetrical MIMO wireless communication. The method continues by, when the number of transmission antennas does not exceed the number of reception antennas, using spatial multiplexing for the asymmetrical MIMO wireless communication.
    Type: Application
    Filed: May 20, 2010
    Publication date: September 2, 2010
    Applicant: BROADCOM CORPORATION
    Inventors: Christopher J. Hansen, Jason A. Trachewsky, Nambirajan Seshadri, Kelly Brian Cameron, Hau Thien Tran, Ba-Zhong Shen