Peak-to-Average Power Ratio of OTFS Modulation

Abstract

In this letter, we analyze the peak-to-average power ratio (PAPR) of orthogonal time frequency space modulation (OTFS) waveform. Towards this, we consider modulation symbols on an N x M delay-Doppler grid, where N and M are the number of Doppler and delay bins, respectively. We derive an upper bound on the PAPR of the OTFS signal and show that the maximum PAPR grows linearly with N (and not with M, the number of subcarriers, as observed in conventional multicarrier schemes such as OFDM). We analytically characterize the complementary cumulative distribution function (CCDF) of the PAPR of OTFS with rectangular pulse for large values of N. We present the simulated CCDF of the PAPR of OTFS for different pulse shapes and compare it with those of OFDM and generalized frequency division multiplexing (GFDM). It is shown that OTFS can have better PAPR compared to OFDM and GFDM