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公开(公告)号：DE69700494D1
公开(公告)日：1999-10-14
申请号：DE69700494
申请日：1997-12-02
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CAMPBELL SCOTT PATRICK , RICHARDSON THOMAS J , CURTIS KEVIN RICHARD
Abstract: Embodiments of the invention include a method (10) and apparatus (20) for determining values for data reproduced or retrieved from data storage media such as in holographic memory systems. The method includes approximating (12) the initial value of data members retrieved initially from the data storage medium of interest (by their intensity levels based on an absolute scale), using those approximations collectively to establish (14) one or more threshold levels for defining ranges for the data values to be determined, and determining values for the retrieved data members by comparing (16) the initial data value approximations of the retrieved data members to the established threshold levels. Alternatively, the threshold level(s) are set initially and adjusted iteratively based on the initial approximations of the individual data members until a final established threshold level is established. Advantageously, embodiments of the invention reduce data encoding overhead by using data members to establish comparative threshold levels for the determination of their intended values.
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公开(公告)号：CA2287759C
公开(公告)日：2003-07-29
申请号：CA2287759
申请日：1999-10-29
Applicant: LUCENT TECHNOLOGIES INC
Inventor： SWELDENS WIM , URBANKE RUDIGER L , MARZETTA THOMAS LOUIS , RICHARDSON THOMAS J , HOCHWALD BERTRAND M
Abstract: Messages according to a method of wireless signal transmission are sent as sequences of unitary space-time signals. Each signal is representable as a matrix in which each column represents a respective transmitting antenna of a transmitting array, and each row represents a time segment. Each such matrix is proportional to a complex-valued matrix, all columns of which are mutually orthonormal. A ne w method for creating a constellation of signal matrices comprises providing a n initial signal in the form of a complex, orthonormal matrix. The method further comprises generating a further plurality of matrices by a process that assures that ea ch of the generated matrices is related to the initial matrix as a product of one or more multiplications of the initial matrix by one or more unitary matrices.
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Patent Agency Ranking
公开(公告)号：DE69900421D1
公开(公告)日：2001-12-13
申请号：DE69900421
申请日：1999-03-02
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LAROIA RAJIV , URBANKE RUDIGER L , RICHARDSON THOMAS J
Abstract: We describe an improved method for decreasing the probability of an unacceptably high peak-to-average power ratio in a signal to be transmitted by a Frequency Division Multiplexing (FDM) system, such as a discrete multitone (DMT) system. The method involves generating at least two alternative signal sequences, computing Fourier transforms of the respective alternative signal sequences, and selecting for transmission one of these sequences, based on the Fourier transform computations. More specifically, the selection of one sequence may be based, e.g., on the determination that the Fourier transform of that sequence has an acceptable peak power. Alternatively, a comparison may be made among the Fourier transforms of the respective signal sequences, and selection made of that sequence whose Fourier transform exhibits the lowest peak power.
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公开(公告)号：DE69700494T2
公开(公告)日：2000-05-04
申请号：DE69700494
申请日：1997-12-02
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CAMPBELL SCOTT PATRICK , RICHARDSON THOMAS J , CURTIS KEVIN RICHARD
Abstract: Embodiments of the invention include a method (10) and apparatus (20) for determining values for data reproduced or retrieved from data storage media such as in holographic memory systems. The method includes approximating (12) the initial value of data members retrieved initially from the data storage medium of interest (by their intensity levels based on an absolute scale), using those approximations collectively to establish (14) one or more threshold levels for defining ranges for the data values to be determined, and determining values for the retrieved data members by comparing (16) the initial data value approximations of the retrieved data members to the established threshold levels. Alternatively, the threshold level(s) are set initially and adjusted iteratively based on the initial approximations of the individual data members until a final established threshold level is established. Advantageously, embodiments of the invention reduce data encoding overhead by using data members to establish comparative threshold levels for the determination of their intended values.
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公开(公告)号：AU2804999A
公开(公告)日：1999-11-18
申请号：AU2804999
申请日：1999-05-10
Applicant: LUCENT TECHNOLOGIES INC
Inventor： BRUCKSTEIN ALFRED M , RICHARDSON THOMAS J
Abstract: A method and system for watermarking and recovering a watermarked digitized image for subsequent authentication. The digitized image comprises spatial domain data signals reproduced from an original image. A transformer transforms the spatial domain data signals into frequency domain data signals, including respective magnitude and phase data signal components. Information is embedded into the magnitude data signals to develop modified data signals and the modified data signals are converted from the frequency domain to the spatial domain to generate the watermarked digitized image. For recovery, a second transformer transforms the spatial domain data signals comprising the respective original digitized image and watermarked digitized image into respective frequency domain dataset signals. A comparator responsive to the two transformer outputs compares the respective frequency domain dataset signals to identify the watermark and verify the authenticity of the image reproduction.
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公开(公告)号：DE69904284D1
公开(公告)日：2003-01-16
申请号：DE69904284
申请日：1999-11-30
Applicant: LUCENT TECHNOLOGIES INC
Inventor： HOCHWALD BERTRAND M , MARZETTA THOMAS LOUIS , RICHARDSON THOMAS J , SWELDENS WIM , URBANKE RUDIGER L
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公开(公告)号：DE69900421T2
公开(公告)日：2002-07-11
申请号：DE69900421
申请日：1999-03-02
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LAROIA RAJIV , URBANKE RUDIGER L , RICHARDSON THOMAS J
Abstract: We describe an improved method for decreasing the probability of an unacceptably high peak-to-average power ratio in a signal to be transmitted by a Frequency Division Multiplexing (FDM) system, such as a discrete multitone (DMT) system. The method involves generating at least two alternative signal sequences, computing Fourier transforms of the respective alternative signal sequences, and selecting for transmission one of these sequences, based on the Fourier transform computations. More specifically, the selection of one sequence may be based, e.g., on the determination that the Fourier transform of that sequence has an acceptable peak power. Alternatively, a comparison may be made among the Fourier transforms of the respective signal sequences, and selection made of that sequence whose Fourier transform exhibits the lowest peak power.
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