Peak-to-average power reduction method
First Claim
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1. A method for peak-to-average power reduction in a hybrid signal comprising first and second separately modulated signals, the method comprising the steps of:
- obtaining a sample point of the hybrid signal;
defining the sample point by way of a first vector corresponding to the first separately modulated signal and a second vector corresponding to the second separately modulated signal;
adding the first vector to the second vector to obtain a hybrid vector;
comparing the hybrid vector against a maximum desired peak threshold to identify peaks in power;
determining an error vector that reduces the identified peaks in power of the hybrid vector to within the maximum desired peak threshold;
adding the error vector to the second vector to reduce at least one peak in power of the identified peaks in power, andcorrecting a constellation and a spectrum of the second modulated signal following peak determination and peak reduction to yield a corrected second modulated signal, wherein said correcting of the constellation and spectrum comprises the steps of;
demodulating the second separately modulated signal;
correcting all carriers in the demodulated signal;
clipping non-carriers to a mask; and
modulating the corrected second separately modulated signal.
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Abstract
A method of reducing peak-to-average power in a hybrid signal is provided. The method determines peaks in power by defining a sample point by way of a digital vector and an analog vector. The digital and analog vectors are added together to generate a hybrid vector which is used to compare the sample point to the maximum desired peak threshold. An error vector is used to correct the sample point to a desired power level. Once the sample point has been corrected it can be added back to the analog signal and transmitted.
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19 Claims
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1. A method for peak-to-average power reduction in a hybrid signal comprising first and second separately modulated signals, the method comprising the steps of:
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obtaining a sample point of the hybrid signal; defining the sample point by way of a first vector corresponding to the first separately modulated signal and a second vector corresponding to the second separately modulated signal; adding the first vector to the second vector to obtain a hybrid vector; comparing the hybrid vector against a maximum desired peak threshold to identify peaks in power; determining an error vector that reduces the identified peaks in power of the hybrid vector to within the maximum desired peak threshold; adding the error vector to the second vector to reduce at least one peak in power of the identified peaks in power, and correcting a constellation and a spectrum of the second modulated signal following peak determination and peak reduction to yield a corrected second modulated signal, wherein said correcting of the constellation and spectrum comprises the steps of; demodulating the second separately modulated signal; correcting all carriers in the demodulated signal; clipping non-carriers to a mask; and modulating the corrected second separately modulated signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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