Patents by Inventor Parthapratim De
Parthapratim De 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: 7106719Abstract: A code division multiple access user equipment is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated. A column of a channel correlation matrix is determined using the estimated channel response. A spread data vector is determined using the determined column, the estimated channel response, the received combined signal and a fourier transform. Data of the data signals is estimated using the spread data vector.Type: GrantFiled: February 21, 2002Date of Patent: September 12, 2006Assignee: InterDigital Technology CorporationInventors: Parthapratim De, Ariela Zeira, Jung-Lin Pan, Raj Mani Misra
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Publication number: 20060182070Abstract: A method of recovering data for use in a receiver that simultaneously receives a plurality of code division multiple access data signals, each data signal experiencing a similar channel response. A combined signal over the shared spectrum in a time slot is received and sampled. The combined signal comprises the plurality of data signals. The sampled signal is used to estimate the similar channel response, and a channel response matrix is constructed. A channel correlation matrix is constructed based in part on the estimated channel response matrix. A fast Fourier transform (FFT) decomposition of a circulant matrix approximation of the channel correlation matrix, and the sampled data signals, are used to determine a spread data vector. The spread data vector is despread to recover data from the matrix.Type: ApplicationFiled: March 7, 2006Publication date: August 17, 2006Applicant: InterDigital Technology CorporationInventors: Jung-Lin Pan, Parthapratim De, Ariela Zeira
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Patent number: 7072290Abstract: A code division multiple access base station is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated. A column of a channel correlation matrix is determined using the estimated channel response. A spread data vector is determined using the determined column, the estimated channel response, the received combined signal and a fourier transform. Data of the data signals is estimated using the spread data vector.Type: GrantFiled: February 21, 2002Date of Patent: July 4, 2006Assignee: InterDigital Technology CorporationInventors: Parthapratim De, Ariela Zeira, Jung-Lin Pan, Raj Mani Misra
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Patent number: 7054300Abstract: A circuit for use in a receiver receives a plurality of code division multiple access data signals simultaneously. Each data signal experiences a similar channel response. The circuit receives a combined signal over the shared spectrum in a time slot. The combined signal comprises the plurality of data signals. The combined signal is sampled at a multiple of a chip rate of the combined signal. The similar channel response is estimated. A channel response matrix or a channel correlation matrix is constructed based in part on the estimated channel response. A spread data vector is determined based in part on a fast Fourier transform (FFT) decomposition of a circulant version of the channel response matrix or channel correlation matrix. The spread data vector is despread to recover data from the matrix.Type: GrantFiled: April 7, 2005Date of Patent: May 30, 2006Assignee: InterDigital Technology CorporationInventors: Jung-Lin Pan, Parthapratim De, Ariela Zeira
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Publication number: 20050180495Abstract: A circuit for use in a receiver receives a plurality of code division multiple access data signals simultaneously. Each data signal experiences a similar channel response. The circuit receives a combined signal over the shared spectrum in a time slot. The combined signal comprises the plurality of data signals. The combined signal is sampled at a multiple of a chip rate of the combined signal. The similar channel response is estimated. A channel response matrix or a channel correlation matrix is constructed based in part on the estimated channel response. A spread data vector is determined based in part on a fast Fourier transform (FFT) decomposition of a circulant version of the channel response matrix or channel correlation matrix. The spread data vector is despread to recover data from the matrix.Type: ApplicationFiled: April 7, 2005Publication date: August 18, 2005Applicant: InterDigital Technology CorporationInventors: Jung-Lin Pan, Parthapratim De, Ariela Zeira
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Patent number: 6904036Abstract: A time division duplex using code division multiple access base station receives a plurality of data signals in a time slot. Each data signal experiences a similar channel response. The base station receives a combined signal over the shared spectrum in a time slot. The combined signal comprises the plurality of data signals. The combined signal is sampled at a multiple of a chip rate of the combined signal. The similar channel response is estimated. A channel response matrix or a channel correlation matrix is constructed based on in part the estimated channel response. A spread data vector is determined based on in part a fast fourier transform (FFT) decomposition of a circulant version of the channel response or channel correlation matrix. The spread data vector is despread to recover data from the matrix.Type: GrantFiled: February 15, 2002Date of Patent: June 7, 2005Assignee: InterDigital Technology CorporationInventors: Jung-Lin Pan, Parthapratim De, Ariela Zeira
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Patent number: 6885654Abstract: A combined signal is received over a shared spectrum in a time slot in a time division duplex communication system using code division multiple access. Each data signal experiences a similar channel response. The similar channel response is estimated. A matrix representing a channel of the data signals based on in part the estimated channel response is constructed. A spread data vector is determined based on in part a fast fourier transform (FFT) decomposition of a circulant version of the channel matrix. The spread data vector is despread to recover data from the received combined signal.Type: GrantFiled: March 22, 2001Date of Patent: April 26, 2005Assignee: InterDigital Technology CorporationInventors: Jung-Lin Pan, Parthapratim De, Ariela Zeira
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Patent number: 6879578Abstract: A time division duplex using code division multiple access user equipment receives a plurality of data signals in a time slot. Each data signal experiences a similar channel response. The user equipment receives a combined signal over the shared spectrum in a time slot. The combined signal comprises the plurality of data signals. The combined signal is sampled at a multiple of a chip rate of the combined signal. The similar channel response is estimated. A channel response matrix or a channel correlation matrix is constructed based on in part the estimated channel response. A spread data vector is determined based on in part a fast fourier transform (FFT) decomposition of a circulant version of the channel response or channel correlation matrix. The spread data vector is despread to recover data from the matrix.Type: GrantFiled: February 15, 2002Date of Patent: April 12, 2005Assignee: InterDigital Technology CorporationInventors: Jung-Lin Pan, Parthapratim De, Ariela Zeira
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Patent number: 6625203Abstract: K data signals are transmitted over a shared spectrum in a code division multiple access communication system. A combined signal is received and sampled over the shared spectrum. The combined signal has the K transmitted data signals. A combined channel response matrix is produced using the codes and impulse responses of the K transmitted data signals. A block column of a combined channel correlation matrix is determined using the combined channel response matrix. Each block entry of the block column is a K by K matrix. At each frequency point k, a K by K matrix &Lgr;(k) is determined by taking the fourier transform of the block entries of the block column. An inverse of &Lgr;(k) is multiplied to a result of the fourier transform. Alternately, forward and backward substitution can be used to solve the system. An inverse fourier transform is used to recover the data from the K data signals.Type: GrantFiled: December 31, 2001Date of Patent: September 23, 2003Assignee: InterDigital Technology CorporationInventors: Parthapratim De, Jung-Lin Pan, Ariela Zeira
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Patent number: 6608859Abstract: A code division multiple access base station receives K data signals over a shared spectrum. The base station receives and samples a combined signal having the K transmitted data signals. A combined channel response matrix is produced. A block column of a cross correlation matrix is determined using the combined channel response matrix. Each block entry of the block column is a K by K matrix. Each block entry of the block column is a K by K matrix. A fourier transform of a complex conjugate transpose of the combined channel response matrix multiplied to the combined signal samples is taken. An inverse of a fourier transform of each block entry is multiplied to a result of the fourier transform to produce a fourier transform of the data vector. An inverse fourier transform of the data vector fourier transform is taken to produce data of the K signals.Type: GrantFiled: February 20, 2002Date of Patent: August 19, 2003Assignee: InterDigital Technology CorporationInventors: Parthapratim De, Jung-Lin Pan, Ariela Zeira
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Patent number: 6563812Abstract: A receiver in a code-division-multiple-access network includes a forward detector, a first feedback detector, a set of second feedback detectors, a slicer and an arithmetic logic unit for detecting each one of the multiple transmitted signals. The forward detector has an input connected to receive the sum of the multiple transmitted signals. The arithmetic logic has an input connected to an output of the forward detector. The slicer has an input connected to an output of the arithmetic logic unit. The first feedback detector has an input connected to an output of the slicer and an output is connected to the input of the arithmetic logic unit. Each of the second feedback detectors has an input connected to the output of a slicer for each of the other slicers and an output is connected to the input of the arithmetic logic unit. The output of the slicer provides the detected signal, for each transmitter.Type: GrantFiled: October 12, 1999Date of Patent: May 13, 2003Assignee: Mitsubishi Electric Research Laboratories, Inc.Inventor: Parthapratim De
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Publication number: 20030043767Abstract: A time division duplex using code division multiple access user equipment receives a plurality of data signals in a time slot. Each data signal experiences a similar channel response. The user equipment receives a combined signal over the shared spectrum in a time slot. The combined signal comprises the plurality of data signals. The combined signal is sampled at a multiple of a chip rate of the combined signal. The similar channel response is estimated. A channel response matrix or a channel correlation matrix is constructed based on in part the estimated channel response. A spread data vector is determined based on in part a fast fourier transform (FFT) decomposition of a circulant version of the channel response or channel correlation matrix. The spread data vector is despread to recover data H from the matrix.Type: ApplicationFiled: February 15, 2002Publication date: March 6, 2003Applicant: InterDigital Technology CorporationInventors: Jung-Lin Pan, Parthapratim De, Ariela Zeira
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Patent number: 6526093Abstract: In a receiver, an adaptive decision feedback equalizer receives broadcast signals having multipath interference. The equalizer includes a feed-forward, a feedback, and a partial feedback forward filter. The equalizer also includes a slicer and two accumulators. An output from the slicer is processed by the feedback filter and the partial feedback filter. The output from the feedback filter is subtracted from output of the feed-forward filter to form the input to the slicer, and the output of the partial feedback filter is subtracted from the received signal to form the input for the feed-forward filter to reduce the multipath interference.Type: GrantFiled: March 4, 1999Date of Patent: February 25, 2003Assignee: Mitsubishi Electric Research Laboratories, INCInventors: Jay Bao, Parthapratim De, Tommy C. Poon
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Publication number: 20030035392Abstract: A combined signal is received over a shared spectrum in a time slot in a time division duplex communication system using code division multiple access. Each data signal experiences a similar channel response. The similar channel response is estimated. A matrix representing a channel of the data signals based on in part the estimated channel response is constructed. A spread data vector is determined based on in part a fast fourier transform (FFT) decomposition of a circulant version of the channel matrix. The spread data vector is despread to recover data from the received combined signal.Type: ApplicationFiled: March 22, 2001Publication date: February 20, 2003Inventors: Jung-Lin Pan, Parthapratim De, Ariela Zeira
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Publication number: 20030026236Abstract: A code division multiple access user equipment receives K data signals over a shared spectrum. The user equipment receives and samples a combined signal having the K transmitted data signals. A combined channel response matrix is produced. A block column of a cross correlation matrix is determined using the combined channel response matrix. Each block entry of the block column is a K by K matrix. Each block entry of the block column is a K by K matrix. A fourier transform of a complex conjugate transpose of the combined channel response matrix multiplied to the combined signal samples is taken. An inverse of a fourier transform of each block entry is multiplied to a result of the fourier transform to produce a fourier transform of the data vector. An inverse fourier transform of the data vector fourier transform is taken to produce data of the K signals.Type: ApplicationFiled: February 20, 2002Publication date: February 6, 2003Applicant: InterDigital Technology CorporationInventors: Parthapratim De, Jung-Lin Pan, Ariela Zeira
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Publication number: 20030026325Abstract: A code division multiple access base station receives K data signals over a shared spectrum. The base station receives and samples a combined signal having the K transmitted data signals. A combined channel response matrix is produced. A block column of a cross correlation matrix is determined using the combined channel response matrix. Each block entry of the block column is a K by K matrix. Each block entry of the block column is a K by K matrix. A fourier transform of a complex conjugate transpose of the combined channel response matrix multiplied to the combined signal samples is taken. An inverse of a fourier transform of each block entry is multiplied to a result of the fourier transform to produce a fourier transform of the data vector. An inverse fourier transform of the data vector fourier transform is taken to produce data of the K signals.Type: ApplicationFiled: February 20, 2002Publication date: February 6, 2003Applicant: InterDigital Technology CorporationInventors: Parthapratim De, Jung-Lin Pan, Ariela Zeira
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Publication number: 20030021335Abstract: K data signals are transmitted over a shared spectrum in a code division multiple access communication system. A combined signal is received and sampled over the shared spectrum. The combined signal has the K transmitted data signals. A combined channel response matrix is produced using the codes and impulse responses of the K transmitted data signals. A block column of a combined channel correlation matrix is determined using the combined channel response matrix. Each block entry of the block column is a K by K matrix. At each frequency point k, a K by K matrix &Lgr;(k) is determined by taking the fourier transform of the block entries of the block column. An inverse of &Lgr;(k) is multiplied to a result of the fourier transform. Alternately, forward and backward substitution can be used to solve the system. An inverse fourier transform is used to recover the data from the K data signals.Type: ApplicationFiled: December 31, 2001Publication date: January 30, 2003Applicant: InterDigital Technology CorporationInventors: Parthapratim De, Jung-Lin Pan, Ariela Zeira
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Publication number: 20020159428Abstract: A code division multiple access base station is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated. A cross correlation matrix is determined using the estimated channel response. The spread data vector is determined using order recursions by determining a first spread data estimate using an element from the cross correlation matrix and recursively determining further estimates using additional elements of the cross correlation matrix. Data of the data signals is estimated using the spread data vector.Type: ApplicationFiled: February 21, 2002Publication date: October 31, 2002Applicant: InterDigital Technology CorporationInventors: Parthapratim De, Ariela Zeira, Jung-Lin Pan, Raj Mani Misra
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Publication number: 20020159383Abstract: A code division multiple access user equipment is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated at the multiple of the chip rate. The multiple chip rate estimated channel response is combined as an effective chip rate channel response. A spread data vector is determined using the effective samples, the effective channel response and a fourier transform. Data of the data signals is estimated using the spread data vector.Type: ApplicationFiled: February 21, 2002Publication date: October 31, 2002Applicant: InterDigital Technology CorporationInventors: Parthapratim De, Ariela Zeira, Jung-Lin Pan, Raj Mani Misra
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Publication number: 20020159415Abstract: A time division duplex using code division multiple access base station receives a plurality of data signals in a time slot. Each data signal experiences a similar channel response. The base station receives a combined signal over the shared spectrum in a time slot. The combined signal comprises the plurality of data signals. The combined signal is sampled at a multiple of a chip rate of the combined signal. The similar channel response is estimated. A channel response matrix or a channel correlation matrix is constructed based on in part the estimated channel response. A spread data vector is determined based on in part a fast fourier transform (FFT) decomposition of a circulant version of the channel response or channel correlation matrix. The spread data vector is despread to recover data from the matrix.Type: ApplicationFiled: February 15, 2002Publication date: October 31, 2002Applicant: InterDigital Technology CorporationInventors: Jung-Lin Pan, Parthapratim De, Ariela Zeira