PAPR Reduction in OTFS Using Adaptive Interleaver Scheme with Low Complexity

Abstract:
One of the main challenges with the Orthogonal Time Frequency Space (OTFS) system is its high peak-to-average power ratio (PAPR), as it affects the power efficiency and robustness of the system. The unique signaling scheme of OTFS may make PAPR reduction techniques less efficient compared to orthogonal frequency division multiplexing (OFDM). This paper proposes two efficient PAPR reduction techniques for OTFS signals based on the principle of interleaver. Interleaving is a distortionless technique, and it offers the advantage of avoiding spectral regrowth and ensuring that reliability remains unaffected. Due to the high computational complexity of the interleaver-based technique, an adaptive interleaver is proposed. This technique has been shown to effectively reduce the PAPR of OTFS signals, with the benefit of low complexity and giving the same performance as a conventional interleaver-based technique. The proposed adaptive interleaver reduces complexity by up to 48.5% compared to the conventional interleaver.