Peak-To-Average Power Ratio Analysis For Embedded Pilot And Superimposed Pilot Aided OTFS Waveform

Abstract

Peak-to-average-power-ratio (PAPR) is one of the key performance metrics for Orthogonal time-frequency space (OTFS) waveform which critically depends on its transmit frame structure. On the other hand, estimation of the wireless channel in delay-Doppler (DD) for OTFS scheme, also depends on the structure of transmit frame. In this paper, we thus analyse the PAPR for OTFS waveform considering various frame structures based on different channel estimation techniques. In particular, we consider transmit frame structures for embedded-pilot (EP) and superimposed-pilot (SP) aided channel estimation techniques. Through numerical simulations, we compare the effect of these two different DD transmit frame structures on PAPR performances of the OTFS systems. To achieve PAPR reduction, we next develop the frameworks to implement selected-mapping (SLM) and partial transmit sequence (PTS) techniques using the aforementioned frame structures. We perform computational complexity calculations and numerical simulations to demonstrate the efficacy of the proposed frameworks.