A polynomial phasing scheme to realize minimum crest factor for multicarrier transmission

Abstract

High peak-to-average power ratio (PAPR) in multi-carrier systems such as OFDM can significantly reduce power efficiency and performance. Existing methods to mitigate this problem are known in three major categories, i.e. clipping /filtering, convex optimisation and stochastic approach. In this paper, a polynomial phasing scheme is proposed to achieve maximum PAPR reduction for a multicarrier OFDM signal. Using this scheme, each subcarrier phase is adjusted by a polynomial function of the subcarrier index. The coefficients of such polynomial function can be determined at the transmitter by a search method, and can be conveyed using existing pilot tones. The scheme promising maximum PAPR reduction with no distortion to the spectral mask or loss in data rate requires little change to existing OFDM standards.