Apparatuses and a method for reducing peak power in a transmitter of telecommunications systems
First Claim
1. An apparatus for reducing peak power in a transmitter for use in telecommunications system, by non-linear processing of an input main signal, where the apparatus comprises successive processing stages, each stage of said apparatus comprises:
- a peak finder to;
find, in a present stage, at least one peak of said input main signal exceeding a predetermined threshold level, andmake a list (L0) comprising information on each found peak or information on a number of a largest found peak(s);
a peak selector to;
receive, from said peak finder, said list (L0),receive, from each preceding stage, if any, a list (Li) comprising information on unreduced peaks and a stage number,select, from said lists (L0, Li), at least one peak (P) to be reduced, anddetermine based on said stage number, a fractional sample shift value (FSi) of the stage in which said selected peak (P) was initially found;
a kernel selector to select, for each selected peak (P) to be reduced, a kernel signal (Ki) that is fractionally-sample shifted with a fractional sample shift value that is equal to a sum of all fractional sample shift values, starting from the determined fractional sample shift value (FSi) up to the present stage (10);
a kernel manipulator to scale, rotate, and cyclically shift the fractionally-sample shifted kernel signal (Ki) based on information on the selected peak (P); and
a combiner to reduce at least the selected peak (P) by generating a peak reduced signal through combination of the scaled, rotated, and shifted kernel signal (Ki) with a delayed version of the input main signal.
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Abstract
The present invention relates to an apparatus (100), a base station (500) and a method for reducing peak power of an input signal (1) using successive processing stages (10). Each stage (10) comprises a peak finder (11) arranged to find at least one peak of the input signal (1) exceeding a threshold level, and to make a list (LO) comprising information on a number of the highest peaks or information on each peak; a peak selector (12) adapted to receive the list (LO) and to receive, from each preceding stage (10), a list (Li) with information on unreduced peaks and the stage number. The peak selector (12) further selects from all lists a peak (P) to be reduced and determines a fractional sample shift value (FSi) of the stage in which the selected peak was found. Each stage (10) further comprises a kernel selector that selects a kernel signal (Ki) that is fractionally sample shifted with the sum of all fractional shift values, starting from the shift value (FSi) up to the present stage. Each stage (10) also comprises a kernel manipulator (14) that manipulates the selected kernel signal based on information on the selected peak (P). Each stage (10) further comprises a combiner (15) that reduces the selected peak (P) by combining the manipulated kernel signal with a delayed version of the input signal (1).
15 Citations
18 Claims
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1. An apparatus for reducing peak power in a transmitter for use in telecommunications system, by non-linear processing of an input main signal, where the apparatus comprises successive processing stages, each stage of said apparatus comprises:
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a peak finder to; find, in a present stage, at least one peak of said input main signal exceeding a predetermined threshold level, and make a list (L0) comprising information on each found peak or information on a number of a largest found peak(s); a peak selector to; receive, from said peak finder, said list (L0), receive, from each preceding stage, if any, a list (Li) comprising information on unreduced peaks and a stage number, select, from said lists (L0, Li), at least one peak (P) to be reduced, and determine based on said stage number, a fractional sample shift value (FSi) of the stage in which said selected peak (P) was initially found; a kernel selector to select, for each selected peak (P) to be reduced, a kernel signal (Ki) that is fractionally-sample shifted with a fractional sample shift value that is equal to a sum of all fractional sample shift values, starting from the determined fractional sample shift value (FSi) up to the present stage (10); a kernel manipulator to scale, rotate, and cyclically shift the fractionally-sample shifted kernel signal (Ki) based on information on the selected peak (P); and a combiner to reduce at least the selected peak (P) by generating a peak reduced signal through combination of the scaled, rotated, and shifted kernel signal (Ki) with a delayed version of the input main signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for reducing peak power in a transmitter by non-linear processing of an input main signal using successive processing stages, where, for each stage (10), said method comprises:
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receiving, from each preceding stage, if any, a list (Li) comprising information on unreduced peaks and comprising a stage number of said preceding stage; finding, in a present stage, at least one peak of said input main signal exceeding a predetermined threshold level and making a list (L0) comprising information on each found peak or information on a number of a largest found peak(s); selecting, from said lists (L0, Li), at least one peak to (P) to be reduced and determining based on said stage number, a fractional sample shift value (FSi) of the stage in which said selected peak (P) was initially found; selecting, in the present stage, a kernel signal (Ki) that is fractionally-sample shifted with a fractional sample shift value that is equal to a sum of all fractional sample shift values, starting from the determined fractional sample shift value (FSi) up to the present stage (10); manipulating the selected fractionally sample shifted kernel signal (Ki) by scaling, rotating, and cyclically shifting the fractionally-sample shifted kernel signal based on information on said selected peak (P) to be reduced; and generating a signal by reducing said selected peak (P) through combination of the scaled, rotated, and cyclically shifted selected kernel signal with a delayed version of the input main signal. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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Specification