Absolute Valued Message Passing-Based PAPR Reduction in OTFS under Fading Channel Conditions

Orthogonal Time-Frequency Space (OTFS) modulation presents significant advantages over conventional modulations such as OFDM, particularly for high mobility communication environments, by functioning optimally within doubly dispersive channels. OTFS, however, carries an important drawback common to multicarrier modulations the high Peak-to-Average Power Ratio (PAPR) which contributes to diminished power amplifier efficiency and increased distortions caused by nonlinearity. This work proposes an Absolute Valued Message Passing (AVMP) detector, tailored for OTFS systems under fading channel environments. It is tested using Bit Error Rate (BER) and Complementary Cumulative Distribution Function (CCDF) of PAPR metrics through sophisticated MATLAB simulation under different Signal-to-Noise Ratios (SNR) and different orders of modulations (128-QAM, 256-QAM, 512-QAM). Results explicitly show that the AVMP detector consistently has better BER and significantly less PAPR than conventional techniques MP-OTFS, ZF-OTFS, conventional OTFS, and OFDM. These achievements confirm the competence of AVMP to upgrade OTFS modulation, significantly boosting communication reliability and efficiency for stochastic wireless environments.