Patent ID: 7792200

Claim:
A transmitter for transmitting payload data during a transmission time interval using multi-carrier transmission, where subcarriers are selected to be used for peak-to-average power ratio reduction, comprising: a multi-carrier modulator for modulating multiple subcarrier frequencies with payload data to be transmitted and providing a modulated signal for transmission during the transmission time interval; peak detection circuitry for detecting and extracting one or more peaks in the modulated signal to be reduced; Fourier transformation circuitry for performing a Fourier transform operation on the extracted one or more peaks to generate a peaks frequency spectrum; processing circuitry for processing the peaks frequency spectrum using the frequency spectrum of the selected subcarriers to produce a peaks compensation frequency spectrum; inverse Fourier transformation circuitry for performing an inverse Fourier transform operation on the peaks compensation frequency spectrum to generate a peaks compensation signal in the time domain; a compensation circuit for using the peaks compensation signal to modify the modulated signal to obtain a modified modulated signal with reduced peak-to-average power ratio; a digital-to-analog converter for converting the modified modulated signal with reduced peak-to-average power ratio into an analog signal; and a power amplifier for amplifying the analog signal and providing an output signal to be transmitted.