A Novel PAPR Reduction Method Based on Grid Reservation in Delay-Doppler Domain for OTFS Systems

Orthogonal Time Frequency Space (OTFS) modulation proposed in recent years has received much attention due to its ability to maintain good performance in environments with high frequency dispersion. However, the OTFS system has an inherent high peak-to-average power ratio (PAPR) problem, which impairs the efficiency of power amplifiers. In this paper, we propose a novel PAPR reduction method for OTFS systems, which first introduces the grid reservation (GR) scheme in the delay-Doppler (DD) domain. This proposed method reserves a small portion of the grids for carrying the preset clipping signals (PCS), thus reducing the signal PAPR while introducing none distortions to original signals. Simulation results indicate that the PAPR of OTFS signals can be reduced significantly at the cost of little transmission resources, without degradation of the bit error rate (BER) performance.