A Permutated Partial Transmit Sequence Scheme for PAPR Reduction in Polar-Coded OFDM-IM Systems

In this article, a permutated partial transmit sequence (PTS) scheme is proposed to reduce the peak-to-average-power ratio (PAPR) in polar-coded orthogonal frequency division multiplexing with index modulation (OFDM-IM) systems without side-information (SI) transmission. For generating candidate signals, the proposed PTS method combines two operations of phase rotations and frequency-domain permutations by implementing circular shifting and factor multiplications in time domain, where the phase rotation factors are determined by the frozen bits of polar codes. Additionally, according to the transmitting and polar-coded structures, an SI-free decoder based on successive cancellation lists (SCL) algorithm is developed at the receiving end. Compared with conventional PTS and existing PAPR reduction schemes, the proposed PTS scheme exhibits significantly higher PAPR reduction performance with less complexity. Based on stimulation results, the proposed SI-free receiver is able to achieve error performance similar to that with the receiver utilizing perfect side information in both Additive White Gaussian noise (AWGN) and frequency selective channels.