Low-Complexity Adaptive PTS Technique for Reducing PAPR in OTFS Systems

Abstract:
The peak-to-average power ratio (PAPR) is a significant challenge in orthogonal time frequency space (OTFS) systems, as it affects the power efficiency and robustness of the system. Due to the unique signaling scheme of OTFS, which avoids linear combinations in the time domain, the PAPR techniques may not be an efficient as in orthogonal frequency division multiplexing (OFDM). So, this paper proposes two techniques, optimum partial transmit sequence (PTS) and adaptive PTS, to reduce the PAPR of OTFS signals without causing spectral regrowth. Due to the computational complexity of the optimum PTS technique, we propose an adaptive PTS technique. This technique effectively reduces the PAPR of OTFS signals with the benefits of low complexity and performance similar to that of optimum PTS. The proposed adaptive PTS reduces complexity by up to 87.1% compared to the optimum PTS. Moreover, the proposed adaptive PTS exhibits increased robustness as the number of subcarriers and symbols increases, making it a desirable solution for high-density communication systems and real-world applications.