A METHOD AND A TRANSMITTER TO REDUCE PEAK-TO-AVERAGE POWER RATIO IN AN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXED SIGNAL

摘要

This invention relates to a method of reducing peak-to-average power ratio in an orthogonal frequency division multiplexed, hereinafter referred to as OFDM, signal (10), the method comprising the steps of modulating (66) a set of subcarriers with a set of data symbol vectors to produce a first modulated signal; limiting (78) the magnitude of the first modulated signal to produce a first limited modulated signal; demodulating (80) the first limited modulated signal to recover distorted input symbol vectors, constraining (84) the distorted input symbol vectors to values greater than or equal to a minimum threshold value to produce constrained data symbol vectors; constraining out-of-band spectral components to lie within a predetermined mask (112) by suppressing their magnitude and preserving their phase; and remodulating (88) the constrained data symbol vectors.