Xilinx, Inc.

Macrovision Corporation

Integrated Device Technology, Inc.

Gregory C Copeland

John O Ryan

E Fraser Morrison

Kaushik Barman

A method relates generally to data transmission. In such a method, a peak detector detects a signal peak of an input signal exceeding a threshold amplitude. This detecting includes sampling the input signal at a sampling frequency to provide a sampled signal. The sampling frequency is in a range greater than a bandwidth frequency of a carrier signal used for providing the input signal and less than twice the bandwidth frequency. Samples of the sampled signal proximate to the signal peak are interpolated to provide a reconstructed peak. A cancellation pulse is applied by a cancellation pulse generator to the samples to reduce the signal peak. A version of the input signal is output after application of the cancellation pulse.

Pulse cancellation crest factor reduction with a low sampling rate

An apparatus relates generally to multi-path digital predistortion. In this apparatus, a single-band digital predistorter engine has first and second sample paths. An input stage is coupled to receive input samples and configured to separate them into first samples and second samples. The input stage provides first and second magnitudes for the first and second samples, respectively. A first set of digital predistorters receives the first samples, the first magnitudes and the second magnitudes. A second set of digital predistorters receives the second samples, the second magnitudes and the first magnitudes. An output stage is coupled to receive predistorted outputs from the first set of digital predistorters and the second set of digital predistorters and is configured to provide a digital predistorted composite signal from the first set of digital predistorters and the second set of digital predistorters.

Multi-path digital pre-distortion

An apparatus for peak detection includes a peak identification unit configured to determine an identifier of a peak location; a first differential filter configured to provide coefficients for a first polynomial; a fractional locater configured to determine a fractional location of a peak based on the coefficients for the first polynomial and the identifier of the peak location; and a first fractional interpolator to determine a first peak amplitude based on the fractional location of the peak and the coefficients for the first polynomial.

Peak detection in signal processing

A system for crest factor reduction (CFR) includes a peak detector configured to receive an input signal (x); a running maximum filter configured to generate a scaling factor based on a window gain (G) and a filter length, wherein the window gain (G) is based on the input signal (x) and a threshold value (T); a window CFR gain filter configured to generate a gain correction (F) based on the scaling factor and the filter length; a delay configured to delay the input signal (x) to generate a delayed input signal; a multiplier configured to multiply the gain correction (F) by the delayed input signal to obtain a peak correction value; and an adder configured to determine an output signal (y) based on the peak correction value and the delayed input signal.

Crest factor reduction

An apparatus relates generally to crest factor reduction. In this apparatus, a finite impulse response filter provides a first cancellation pulse and a second cancellation pulse. A first adder is coupled to receive an input signal and the first cancellation pulse to provide a first difference signal. A peak engine is coupled to receive the first difference signal to provide a cancellation pulse value responsive to the first difference signal. The finite impulse response filter is coupled to receive the cancellation pulse value to provide each of the first cancellation pulse and the second cancellation pulse. A delay is coupled to receive the input signal to provide a delayed input signal. A second adder is coupled to receive the delayed input signal and the second cancellation pulse to provide a second difference signal. The second difference signal is a crest factor reduced version of the delayed input signal.

Cancellation pulse crest factor reduction

An apparatus relates generally to multiband power modulation. In such an apparatus, there is a first power supply and a second power supply. The first power supply and the second power supply are each narrow-banded. A digital predistorter is coupled to provide separate bands of a modulation signal for respective input of a first band of the bands to the first power supply and a second band of the bands to the second power supply. The first power supply generates a first power at a first center frequency. The second power supply generates a second power at least at a second center frequency spaced apart from the first center frequency for a wide-band configuration. The second power output from the second power supply is coupled to the first power output from the first power supply to provide a multiband power modulation output.

Multiband envelope tracking power amplifier

A method and apparatus for equalizing a received quadrature amplitude modulated signal is disclosed. To equalize the signal, a band edge equalizer (BEE) is used in combination with a symbol spaced equalizer (SSE) and possibly a decision feedback equalizer (DFE). The equalizer's are used along a series path to equalize the QAM signal in a series of equalization operations. By separating the equalization of the signal to separate equalizers, the cost of the equalization can be reduced without substantially affecting performance. In particular, band edge equalizing the QAM signal and symbol space equalizing the symbol can reduce the number of multiplies per second required by any particular equalizer. Accordingly, the equalizers used can be less expensive. Also, using a decimating circuit between the BEE and the SSE that decimates the sample rate of the signal being provided to the SSE can further reduce the number of multiplies per second that must be performed by the SSE. Clock recovery and synchronization circuits have also been disclosed.

Method for equalization of a quadrature amplitude modulated signal

A system for providing security and tracking data for rental video media, including digital video discs and digital video cassettes. Those new formats for video players and media allow for inclusion of security features which both allow tracking of rental of such media and prevent unauthorized rental thereof. Each player includes a decision circuit which plays a particular disc (or tape) only if a player identification number recorded on a special separate authorization memory card is the same as the player identification stored in the player, and if a movie identification number optically read from the disc matches a movie identification number recorded on the special card. A corresponding apparatus is provided at the video rental store which, at the time of rental, records on the authorization card in encrypted form the movie identification number and the number of the particular disc player for which that rental is intended. The encryption uses the private key of a public key system, the public key and the modulus being pre-recorded on the optical portion of the disc.

Video media security and tracking system

A video disc designed for providing security and tracking data in the rental video media market. Those new formats for video players and media allow for inclusion of security features which both allow tracking of rental of such media and prevent unauthorized rental thereof Each player includes a decision circuit which plays a particular optical disc only if a player identification number recorded on a special separate magnetic track on the optical disk is the same as the player identification stored in the player, and if a movie identification number optically read from the disc matches a movie identification number recorded on the special separate magnetic track. A corresponding apparatus is provided at the video rental store which, at the time of rental, records on a magnetic portion of the media in encrypted form the movie identification number and the number of the particular disc player for which that rental is intended. The authorization encryption uses the private key of a public key system, the public key and the modulus being pre-recorded on the optical portion of the disc.

A method and apparatus for inserting source identification data into a video signal prior to its transmission, recording or display. The source identification data (Finger Print) is injected into the active picture area of a video signal without disturbing the viewing of the video signal and the data is retrieved by a data reader, called a Fingerprint Reader. The data injection or 'fingerprinting' process consists of dynamically offsetting the video pedestal to carry information which can then be read back from any videotape made from the output of the data-injecting unit. In particular, the fingerprint carries the ID number of the unit used and the current date. The offset lasts for one entire field and has an amplitude of approximately 0.5 IRE-- that is, a given field either has the nominal setup or a setup value differing from nominal by 0.5 IRE. The data is repeated every 128 fields in order to provide ample samples for the reader to detect and display the source identification data.

Apparatus for inserting blanked formatted fingerprint data (source ID,

A method and apparatus for inserting source identification data into a video signal prior to its transmission, recording or display. The source identification data (Finger Print) is injected into the active picture area of a video signal without disturbing the viewing of the video signal and the data is retrieved by a data reader, called a Fingerprint Reader. The data injection or 'fingerprinting' process consists of dynamically offsetting the video pedestal to carry information which can then be read back from any videotape made from the output of the data-injecting unit. In particular, the fingerprint carries the ID number of the unit used and the current date. The offset lasts for one entire field and has an amplitude of approximately 0.5 IRE--that is, a given field either has the nominal setup or a setup value differing from nominal by 0.5 IRE. The data is repeated every 128 fields in order to provide ample samples for the reader to detect and display the source identification data.

Video finger print method and apparatus

A method and apparatus for copyright protection for various recording media such as Digital Video Discs (DVDs) uses a combination of a Video Finger Print Signal and an Authenticating Signature to permit the player to handle either copy-protected or non-copy-protected media, in a manner that is difficult to compromise. Both a Video Finger Print Signal and an Authenticating Signature are recorded on the media only when copy-protection is required. The nature of this Authenticating Signature is such that it will not be transferred to illicit copies made on CD recorders. When either an original protected or an original non-protected disk is played, the presence or absence of the Authenticating Signature causes the player to correctly play the program video. All original DVDs therefore play normally. When a copy of a non-protected CD is played, the absence of the Video Print Signal also causes the player to correctly playback the video signal data. However, when a copy of a protected CD is played, the absence of the Authenticating Signature causes the player to prohibit the disk from playing normally.

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Savannah, TX, United States of America

Gregory C Copeland