Pulse cancellation crest factor reduction with a low sampling rate
AssigneeXilinx, Inc.
InventorsKaushik Barman, Gregory C. Copeland
Life of this patent
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Abstract
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.
Claims20
A method for data transmission, comprising:
- detecting by a peak detector a signal peak of an input signal exceeding a threshold amplitude;
- wherein the detecting comprises sampling the input signal at a sampling frequency to provide a sampled signal, the sampling frequency 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;
- interpolating samples of the sampled signal proximate to the signal peak with a bandlimited interpolation to provide a reconstructed peak;
- applying a cancellation pulse by a cancellation pulse generator to the samples to reduce the signal peak;
- and
- outputting a version of the input signal after application of the cancellation pulse.
An apparatus for data transmission, comprising:
- a peak detector for receiving an input signal for detecting a signal peak in the input signal exceeding a threshold amplitude;
- the peak detector for sampling the input signal at a sampling frequency to provide a sampled signal;
- wherein 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;
- the peak detector for interpolating samples of the sampled signal proximate to the signal peak;
- wherein an interpolator of the peak detector is configured to interpolate the samples with a bandlimited interpolation;
- and
- a cancellation pulse generator for applying a cancellation pulse to the input signal to reduce the signal peak.
A system for a transmitter, comprising:
- a peak detector for receiving an input signal for detecting a signal peak in the input signal exceeding a threshold amplitude;
- the peak detector for sampling the input signal at a sampling frequency to provide a sampled signal;
- wherein 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;
- the peak detector having:
- an angle determination block for receiving the input signal for providing an activation signal indicating samples of the sampled signal are associated with a peak;
- a peak-side detector for receiving the activation signal for selecting either a left side order of the samples or a right side order of the samples of the signal peak;
- and
- an interpolator for interpolating either the left side order of the samples or the right side order of the samples selected;
- a cancellation pulse generator for applying a cancellation pulse to the input signal to reduce the signal peak for outputting a version of the input signal;
- and
- a windowed crest factor reduction block for cleaning the version of the input signal.
Dependencies are inferred from the claim text.