Patent ID: 9031144
Filing Date: 2015-05-12
Classification: H04B

Abstract:
1. A peak factor reduction device for reducing peak components included in a transmission signal, wherein the peak factor reduction device generates a cancellation signal to be multiplexed on the transmission signal, and the peak factor reduction device changes an amplitude of the generated cancellation signal according to a signal noise ratio required for the transmission signal and a power level of the transmission signal; the peak factor reduction device includes: a cancellation signal generator that generates the cancellation signal, wherein the cancellation signal generator includes: a peak detector that detects peak components included in the transmission signal; a weight calculator that calculates a weight coefficient of the cancellation signal according to the signal noise ratio and the power level of the transmission signal; and a cancellation signal combining unit that combines a cancellation signal having an amplitude proportional to the calculated weight coefficient, and the weight calculator includes: an SNR correction unit that calculates a logarithmic ratio of the signal noise ratios required for respective wireless systems or respective channels; a filter response characteristic correcting unit that calculates a ratio of transmission power levels corrected with filter characteristics in at least one of the respective wireless systems and the respective channels; and a normalization unit that normalizes the logarithmic ratio of the signal noise ratios calculated by the SNR correction unit and the ratio of the transmission power levels calculated by the filter response characteristic correcting unit to calculate weight coefficients of the transmission signals of the respective wireless systems or the respective channels.