A modified constellation extension scheme with low complexity for PAPR reduction in OFDM systems

High peak-to-average power ratio (PAPR) is one major drawback of orthogonal frequency division multiplexing (OFDM) systems. Recently, the constellation extended scheme (CES) is an active technique for reducing PAPR of OFDM signals. However, this approach needs high computational load and more inverse Fast Fourier transform (IFFT) operations for finding the transmitted signal with minimum PAPR out. Therefore, this paper proposes a modified CES with lower computational load and IFFT operations than the CES in a 16-QAM OFDM system. Our proposed method, which combines the CES with the partial transmit sequences (PTS) technique, is also called CES-PTS. When compared to PTS techniques, our proposed method has no need to transmit side information in the transmitter.