Low-Complexity SLM and PTS Schemes for PAPR Reduction in OFDM Systems

Chin-Liang WANG  Yuan OUYANG  Ming-Yen HSU  

IEICE TRANSACTIONS on Communications   Vol.E92-B   No.7   pp.2420-2425
Publication Date: 2009/07/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E92.B.2420
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Wireless Communication Technologies
inverse fast Fourier transform (IFFT),  orthogonal frequency-division multiplexing (OFDM),  partial transmit sequences (PTS),  peak-to-average power ratio (PAPR) reduction,  selected mapping (SLM),  

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One major drawback of orthogonal frequency-division multiplexing is the high peak-to-average power ratio (PAPR) of the output signal. The selected mapping (SLM) and partial transmit sequences (PTS) methods are two promising techniques for PAPR reduction. However, to generate a set of candidate signals, these techniques need a bank of inverse fast Fourier transforms (IFFT's) and thus require high computational complexity. In this paper, we propose two low-complexity multiplication-free conversion processes to replace the IFFT's in the SLM method, where each conversion process for an N-point IFFT involves only 3N complex additions. Using these proposed conversions, we develop several new SLM schemes and a combined SLM & PTS method, in which at least half of the IFFT blocks are reduced. Computer simulation results show that, compared to the conventional methods, these new schemes have approximately the same PAPR reduction performance under the same number of candidate signals for transmission selection.