Patents by Inventor Sivarama Krishnan Venkatesan
Sivarama Krishnan Venkatesan 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: 8331330Abstract: Techniques for efficient searching in asynchronous systems, such as W-CDMA, as well as multi-mode searching, are disclosed. In one aspect, step one and step three search are performed in a single search engine. In another aspect, a search engine is configurable to search the offsets of a slot in step one search, producing sequential hypothesis energies, and peak detecting and sorting those energies. In yet another aspect, the peak detector and sorter are configurable to perform step one searching or step three/multimode searching. Various other aspects of the invention are also presented. These aspects have the benefit of circuit area and search-time efficiency which translate into reduced costs, increased standby time, increased acquisition speed, higher quality signal transmission, increased data throughput, decreased power, and improved overall system capacity.Type: GrantFiled: April 20, 2010Date of Patent: December 11, 2012Assignee: QUALCOMM IncorporatedInventors: Daisuke Terasawa, Deepu John, Hao Liu, Qiuzhen (Joe) Zou, Sivarama Krishnan Venkatesan
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Patent number: 8189453Abstract: Improvements are provided in an OFDM network that uses superposition coding. A broadcast signal and e.g. a unicast signal are each subjected to OFDM modulation including processing by an IDFT, combined, and transmitted using non-orthogonal transmission resources. In one approach, the respective signals are combined after instead of before the IDFT processing. In specific examples, a respective cyclic prefix is appended to each signal after the IDFT processing but before the respective signals are combined. In another approach, a broadcast pilot signal and e.g. a unicast pilot signal are transmitted concurrently with the broadcast and unicast information signals. The pilot signals are transmitted using the same time and subcarrier resources, but are made more distinguishable by combining each with a respective scrambling or spreading code. In specific examples, embodiments, the unicast pilot signal is used for estimating the data rate for transmission of further unicast information signals.Type: GrantFiled: March 6, 2009Date of Patent: May 29, 2012Assignee: Alcatel LucentInventors: Pantelis Monogioudis, Shirish Nagaraj, Sivarama Krishnan Venkatesan, Harish Viswanathan
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Publication number: 20100202316Abstract: Techniques for efficient searching in asynchronous systems, such as W-CDMA, as well as multi-mode searching, are disclosed. In one aspect, step one and step three search are performed in a single search engine. In another aspect, a search engine is configurable to search the offsets of a slot in step one search, producing sequential hypothesis energies, and peak detecting and sorting those energies. In yet another aspect, the peak detector and sorter are configurable to perform step one searching or step three/multimode searching. Various other aspects of the invention are also presented. These aspects have the benefit of circuit area and search-time efficiency which translate into reduced costs, increased standby time, increased acquisition speed, higher quality signal transmission, increased data throughput, decreased power, and improved overall system capacity.Type: ApplicationFiled: April 20, 2010Publication date: August 12, 2010Applicant: QUALCOMM IncorporatedInventors: Daisuke Terasawa, Deepu John, Hao Liu, Qiuzhen Zou, Sivarama Krishnan Venkatesan
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Patent number: 7756085Abstract: Techniques for efficient searching in asynchronous systems, such as W-CDMA, as well as multi-mode searching, are disclosed. In one aspect, step one and step three search are performed in a single search engine. In another aspect, a search engine is configurable to search the offsets of a slot in step one search, producing sequential hypothesis energies, and peak detecting and sorting those energies. In yet another aspect, the peak detector and sorter are configurable to perform step one searching or step three/multimode searching. Various other aspects of the invention are also presented. These aspects have the benefit of circuit area and search-time efficiency which translate into reduced costs, increased standby time, increased acquisition speed, higher quality signal transmission, increased data throughput, decreased power, and improved overall system capacity.Type: GrantFiled: May 31, 2002Date of Patent: July 13, 2010Assignee: QUALCOMM IncorporatedInventors: Daisuke Terasawa, Deepu John, Hao Liu, Qiuzhen (Joe) Zou, Sivarama Krishnan Venkatesan
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Publication number: 20090175162Abstract: Improvements are provided in an OFDM network that uses superposition coding. A broadcast signal and e.g. a unicast signal are each subjected to OFDM modulation including processing by an IDFT, combined, and transmitted using non-orthogonal transmission resources. In one approach, the respective signals are combined after instead of before the IDFT processing. In specific examples, a respective cyclic prefix is appended to each signal after the IDFT processing but before the respective signals are combined. In another approach, a broadcast pilot signal and e.g. a unicast pilot signal are transmitted concurrently with the broadcast and unicast information signals. The pilot signals are transmitted using the same time and subcarrier resources, but are mad e more distinguishable by combining each with a respective scrambling or spreading code. In specific examples, embodiments, the unicast pilot signal is used for estimating the data rate for transmission of further unicast information signals.Type: ApplicationFiled: March 6, 2009Publication date: July 9, 2009Inventors: Pantelis Monogioudis, Shirish Nagaraj, Sivarama Krishnan Venkatesan, Harish Viswanathan
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Patent number: 7558191Abstract: Improvements are provided in an OFDM network that uses superposition coding. A broadcast signal and e.g. a unicast signal are each subjected to OFDM modulation including processing by an IDFT, combined, and transmitted using non-orthogonal transmission resources. In one approach, the respective signals are combined after instead of before the IDFT processing. In specific examples, a respective cyclic prefix is appended to each signal after the IDFT processing but before the respective signals are combined. In another approach, a broadcast pilot signal and e.g. a unicast pilot signal are transmitted concurrently with the broadcast and unicast information signals. The pilot signals are transmitted using the same time and subcarrier resources, but are made more distinguishable by combining each with a respective scrambling or spreading code. In specific examples, embodiments, the unicast pilot signal is used for estimating the data rate for transmission of further unicast information signals.Type: GrantFiled: September 7, 2006Date of Patent: July 7, 2009Assignee: Alcatel-Lucent USA Inc.Inventors: Pantelis Monogioudis, Shirish Nagaraj, Sivarama Krishnan Venkatesan, Harish Viswanathan
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Publication number: 20080062857Abstract: Improvements are provided in an OFDM network that uses superposition coding. A broadcast signal and e.g. a unicast signal are each subjected to OFDM modulation including processing by an IDFT, combined, and transmitted using non-orthogonal transmission resources. In one approach, the respective signals are combined after instead of before the IDFT processing. In specific examples, a respective cyclic prefix is appended to each signal after the IDFT processing but before the respective signals are combined. In another approach, a broadcast pilot signal and e.g. a unicast pilot signal are transmitted concurrently with the broadcast and unicast information signals. The pilot signals are transmitted using the same time and subcarrier resources, but are made more distinguishable by combining each with a respective scrambling or spreading code. In specific examples, embodiments, the unicast pilot signal is used for estimating the data rate for transmission of further unicast information signals.Type: ApplicationFiled: September 7, 2006Publication date: March 13, 2008Inventors: Pantelis Monogioudis, Shirish Nagaraj, Sivarama Krishnan Venkatesan, Harish Viswanathan
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Patent number: 7200631Abstract: Generally, a method and apparatus are provided for computing a matrix inverse square root of a given positive-definite Hermitian matrix, K. The disclosed technique for computing an inverse square root of a matrix may be implemented, for example, by the noise whitener of a MIMO receiver. Conventional noise whitening algorithms whiten a non-white vector, X, by applying a matrix, Q, to X, such that the resulting vector, Y, equal to Q·X, is a white vector. Thus, the noise whitening algorithms attempt to identify a matrix, Q, that when multiplied by the non-white vector, will convert the vector to a white vector. The disclosed iterative algorithm determines the matrix, Q, given the covariance matrix, K. The disclosed matrix inverse square root determination process initially establishes an initial matrix, Q0, by multiplying an identity matrix by a scalar value and then continues to iterate and compute another value of the matrix, Qn+1, until a convergence threshold is satisfied.Type: GrantFiled: January 10, 2003Date of Patent: April 3, 2007Assignee: Lucent Technologies Inc.Inventors: Laurence Eugene Mailaender, Jack Salz, Sivarama Krishnan Venkatesan
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Patent number: 7167507Abstract: A receiver, system, and method for performing equalization. The receiver includes a multi-channel chip equalizer for receiving a plurality of receive baseband signals and restoring chip pulse shapes of a plurality of transmit baseband signals transmitted by a plurality of transmit antenna to produce a plurality of equalized output streams and a correlator for correlating the plurality of equalized output streams with a correlation signal to reduce gradient noise in the plurality of equalized output streams. The method of equalizing includes receiving a plurality of receive baseband signals and restoring chip pulse shapes of a plurality of transmit baseband signals transmitted by a plurality of transmit antenna to produce a plurality of equalized output streams and correlating the plurality of equalized output streams with a correlation signal to reduce gradient noise in the plurality of equalized output streams.Type: GrantFiled: July 1, 2002Date of Patent: January 23, 2007Assignee: Lucent Technologies Inc.Inventors: Laurence Eugene Mailaender, Sivarama Krishnan Venkatesan, Graeme Kenneth Woodward
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Publication number: 20040139137Abstract: Generally, a method and apparatus are provided for computing a matrix inverse square root of a given positive-definite Hermitian matrix, K. The disclosed technique for computing an inverse square root of a matrix may be implemented, for example, by the noise whitener of a MIMO receiver. Conventional noise whitening algorithms whiten a non-white vector, X, by applying a matrix, Q, to X, such that the resulting vector, Y, equal to Q·X, is a white vector. Thus, the noise whitening algorithms attempt to identify a matrix, Q, that when multiplied by the non-white vector, will convert the vector to a white vector. The disclosed iterative algorithm determines the matrix, Q, given the covariance matrix, K. The disclosed matrix inverse square root determination process initially establishes an initial matrix, Q0, by multiplying an identity matrix by a scalar value and then continues to iterate and compute another value of the matrix, Qn+1, until a convergence threshold is satisfied.Type: ApplicationFiled: January 10, 2003Publication date: July 15, 2004Inventors: Laurence Eugene Mailaender, Jack Salz, Sivarama Krishnan Venkatesan
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Publication number: 20040001426Abstract: A receiver, system, and method for performing equalization. The receiver includes a multi-channel chip equalizer for receiving a plurality of receive baseband signals and restoring chip pulse shapes of a plurality of transmit baseband signals transmitted by a plurality of transmit antenna to produce a plurality of equalized output streams and a correlator for correlating the plurality of equalized output streams with a correlation signal to reduce gradient noise in the plurality of equalized output streams. The method of equalizing includes receiving a plurality of receive baseband signals and restoring chip pulse shapes of a plurality of transmit baseband signals transmitted by a plurality of transmit antenna to produce a plurality of equalized output streams and correlating the plurality of equalized output streams with a correlation signal to reduce gradient noise in the plurality of equalized output streams.Type: ApplicationFiled: July 1, 2002Publication date: January 1, 2004Inventors: Laurence Eugene Mailaender, Sivarama Krishnan Venkatesan, Graeme Kenneth Woodward
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Publication number: 20030147365Abstract: Techniques for efficient searching in asynchronous systems, such as W-CDMA, as well as multi-mode searching, are disclosed. In one aspect, step one and step three search are performed in a single search engine. In another aspect, a search engine is configurable to search the offsets of a slot in step one search, producing sequential hypothesis energies, and peak detecting and sorting those energies. In yet another aspect, the peak detector and sorter are configurable to perform step one searching or step three/multimode searching. Various other aspects of the invention are also presented. These aspects have the benefit of circuit area and search-time efficiency which translate into reduced costs, increased standby time, increased acquisition speed, higher quality signal transmission, increased data throughput, decreased power, and improved overall system capacity.Type: ApplicationFiled: May 31, 2002Publication date: August 7, 2003Inventors: Daisuke Terasawa, Deepu John, Hao Liu, Qiuzhen (Joe) Zou, Sivarama Krishnan Venkatesan