Lowering the Peak to Average Power Ratio by using the PTS method for high-speed application systems

Orthogonal Time-Frequency Space is a promising modulation waveform for beyond-5G or 6G communication systems: superior robustness in high mobility and multipaths is achieved from the delay Doppler domain; however, one severe challenge of this OTFS was its high peak-to-average ratio of power, constraining the linearity of efficient power amplifiers at the transmitter which degrades further the overall performance of the entire system. This paper presents a new application of the Partial Transmit Sequence (PTS) method in reducing the PAPR for OTFS systems, which will ensure compatibility with future wireless networks that have stringent requirements. The PTS is a distortion less technique that divides the input signal into sub-blocks and applies optimized phase factors to reduce the peak power of the signal. It will help to eliminate computational complexity existing with traditional PTS and incorporates enhanced optimization techniques like heuristics algorithm, reduced space searching, hence ensuring a dramatic PAPR reduction with complexity that is minimized. Simulation analysis proved the ability of this proposed work for achieving efficient results in lowering the PAPR with relatively little effect on the bit error rate performances. The results demonstrate the feasibility of PTS-based PAPR reduction to further improve the energy efficiency, spectral efficiency, and reliability of OTFS systems, thereby making it an attractive solution for beyond 5G communication scenarios. The numerical results reveals that the proposed PTS obtain an energy saving of $\mathbf{2 5 \%}$ and reduce the PAPR by 3.9 dB to 5.8 dB.