PAR reduction for OFDM signals based on deep Clipping

One problem of Clipping And Filtering (CAF) is peak regrowth due to the filtering for the clipped signal. This paper proposes a deep clipping method to suppress the peak regrowth and to reduce the Peak-to-Average power Ratio (PAR) of OFDM signals without iteration. In this paper, the mechanism of peak regrowth is described and the deep clipping method is proposed to reduce the peak regrowth effectively. The main idea of deep clipping is modifying the clipping function to “deeply” clip the high amplitude peaks to a level smaller than a clipping level. The proposed method is applied to an OFDM transmission system and achieves significant reduction of the peak regrowth that is equivalent to that by four times repeated CAF. Furthermore, it is shown that in the condition of the same PAR of the final signal, signal quality is improved compared to the normal CAF.