Novel low-complexity post-IFFT PAPR reduction technique by utilising amplitude transforming for OFDM systems

High peak-to-average power ratio (PAPR) is a big obstacle for multicarrier transmission techniques, such as OFDM or DMT. Many PAPR reduction techniques have been proposed in the literature each offering a different combination of system performance, complexity and bandwidth efficiency. Selective mapping (SLM) is one of the most promising techniques which has been shown to offer PAPR reductions of several dBs. However, the fact that the SLM technique requires invoking the IFFT process several times per transmitted OFDM-block increases the system complexity and hence results in long latencies and high power consumption. In this paper, we propose a novel post-IFFT PAPR reduction technique combined with a intelligent strategy for generating a unique time-domain sequence per OFDM block that can minimize the PAPR. It will be shown that our proposed technique has much better overall PAPR reduction ability than the ordinary SLM while at the same time requires several order of magnitude less complexity than that of the SLM technique. © 2007 IEEE.