Low-complexity selected mapping schemes for peak-to-average power ratio reduction in OFDM systems

Orthogonal frequency-division multiplexing (OFDM) is an attractive transmission technique for high-bit-rate communication systems. One major drawback of OFDM is the high peak-to-average power ratio (PAPR) of the transmitter's output signal. The selected mapping (SLM) approach provides good performance for PAPR reduction, but it requires a bank of inverse fast Fourier transforms (IFFTs) to generate a set of candidate transmission signals, and this requirement usually results in high computational complexity. In this paper, we propose a kind of low-complexity conversions to replace the IFFT blocks in the conventional SLM method. Based on the proposed conversions, we develop two novel SLM schemes with much lower complexity than the conventional one; the first method uses only one IFFT block to generate the set of candidate signals, while the second one uses two IFFT blocks. Computer simulation results show that, as compared to the conventional SLM scheme, the first proposed approach has slightly worse PAPR reduction performance and the second proposed one reaches almost the same PAPR reduction performance.

I. Introduction

Owing to the high spectral efficiency and the immunity to multipath channels, orthogonal frequency-division multiplexing (OFDM) is a promising technique for high-rate data transmission [1]. This transmission technique has been adopted for a number of applications, such as the standard for digital radio audio broadcasting (DAB) [2], the standard for digital video broadcasting (DVB) [3], the standard for asymmetric digital subscriber line (ADSL) service over twisted-pair phone lines [4], and the IEEE 802.11a standard for wireless local area networks [5].