Selective peak power reduction
AssigneeNortel Networks Limited
InventorsBradley John Morris, Arthur Thomas Gerald Fuller
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Abstract
The present invention provides a technique for reducing the peak power of a combined signal that has a first signal of a first modulation type and a second signal of a second modulation type. Based on the combined signal, peak reduction distortion is determined. The peak reduction distortion is configured such that, if applied to the entirety of the combined signal, excessive peaks throughout the combined signal would be reduced. However, instead of applying the entirety of the peak reduction distortion, a selected portion of the peak reduction distortion is applied to a corresponding portion of the combined signal to reduce the peak power of the combined signal.
Claims28
A method for reducing peak power associated with a signal comprising:
- generating a first signal of a first modulation type and a second signal of a second modulation type;
- combining the first signal and the second signal to form a combined input signal, wherein the first signal resides in a first frequency band of the combined input signal, the second signal resides in a second frequency band of the combined input signal, and the first frequency band is different than the second frequency band;
- generating peak reduction distortion based on the combined input signal;
- selecting a portion of the peak reduction distortion that corresponds to the first frequency band as a selected portion of the peak reduction distortion;
- and
- applying the selected portion of the peak reduction distortion in the first frequency band of the combined input signal to provide a combined output signal with a reduced peak to average ratio
A communication system comprising:
- upconversion circuitry configured to up-convert a combined output signal to a radio frequency signal for transmission;
- signal processing circuitry associated with the up-conversion circuitry and configured to:
- generate a first signal of a first modulation type and a second signal of a second modulation type;
- combine the first signal and the second signal to form a combined input signal, wherein the first signal resides in a first frequency band of the combined input signal, the second signal resides in a second frequency band of the combined input signal, and the first frequency band is different than the second frequency band;
- generate peak reduction distortion based on the combined input signal;
- selecting a portion of the peak reduction distortion that corresponds to the first frequency band as a selected portion of the peak reduction distortion;
- and
- apply the selected portion of the peak reduction distortion in the first frequency band of the combined input signal to provide the combined output signal with a reduced peak to average power ratio.
A method for reducing peak power associated with a signal comprising:
- generating a first signal of a first modulation type and a second signal of a second modulation type;
- combining the first signal and the second signal to form a combined input signal, wherein the first signal resides in a first frequency band of the combined input signal, the second signal resides in a second frequency band of the combined input signal, and the first frequency band is different than the second frequency band;
- generating peak reduction distortion based on the combined input signal;
- selecting a first portion of the peak reduction distortion that corresponds to the first frequency band and a second portion of the peak reduction distortion that corresponds to the second frequency band;
- and
- applying the first portion of the peak reduction distortion in the first frequency band of the combined input signal and the second portion of the peak reduction distortion in the second frequency band of the combined input signal to provide a combined output signal.
Dependencies are inferred from the claim text.