Impacts of Pulse Shaping Filter on the OTFS Modulation System

In this study, we use Gaussian, raised cosine (RC), and rectangular pulses to examine the orthogonal time frequency space (OTFS) modulation performance in terms of peak power to average power ratio (PAPR). OTFS does not map information symbols in the time-frequency (TF) domain but in the delay-Doppler (DD) domain. Specifically, we incorporate an essential bandpass filter at the receiver's RF front end, a factor often overlooked in existing literature. We analyze the impact of rectangular, RC, and Gaussian pulses on the performance of practical OTFS receivers, and derive precise expressions for both PAPR and power spectral density (PSD). The choice and design of pulse-shaping filters have a significant impact on the performance of OTFS modulation systems. They influence spectral efficiency, inter-symbol interference (ISI), inter-carrier interference (ICI) reduction, TF localization, channel estimation, implementation complexity, robustness to channel variability, and energy efficiency. Careful consideration of these factors can lead to enhanced overall performance of OTFS systems, particularly in challenging communication environments.