Performance evaluation of an iterative PMEPR-reducing technique for OFDM transmission

Some promising techniques to reduce the envelope fluctuations of OFDM signals with a high number of subcarriers combine a nonlinear operation (e.g., an envelope clipping) with a frequency-domain filtering operation, so as to ensure the low-PMEPR (peak-to-mean envelope power ratio) goal while maintaining the spectral efficiency of the corresponding conventional OFDM scheme. However, the filtering operation leads to some envelope fluctuation regrowth, increasing the PMEPR of the transmitted signals. In this paper we consider the repeated use, in an iterative way, of an envelope clipping and a frequency-domain filtering for low-PMEPR OFDM transmission with high spectral efficiency. Based on semi-analytical, statistical characterization of the transmitted frequency-domain blocks, a set of performance results is presented and discussed, showing that the proposed iterative technique can provide improved tradeoffs between power efficiency, spectral efficiency and implementation simplicity.