Frame Partitioning and Interleaving-Based Low PAPR OTFS

In this letter, we propose a simple and efficient low peak-to-average power ratio (PAPR) orthogonal time frequency space (OTFS) scheme, named low PAPR (LP)-OTFS, which does not require side information or signal pre-distortion. The proposed method involves a two-step process. First, the M×N delay-Doppler (DD) domain data frame is partitioned into S sub-blocks along the Doppler axis. Each sub-block is then transformed into the delay-time (DT) domain using a reduced size, i.e., an L(=N/S)-point inverse discrete Fourier transform (IDFT) along the Doppler axis. Next, by performing signal interleaving between sub-blocks, we compensate for the reduced time-domain diversity caused by the smaller sub-block size. Through simulations, we compare the proposed LP-OTFS scheme with both the conventional OTFS and the recently proposed discrete Fourier transform spread OTFS (DFT-s-OTFS) in terms of PAPR and bit error rate (BER). The results demonstrate that the proposed scheme achieves improved BER performance and reduced PAPR. Additionally, a complexity comparison with OTFS and DFT-s-OTFS shows that our proposed method has the lowest complexity.