Time-Frequency Characteristics and PAPR Reduction of OTDM Waveform for 5G and Beyond

In this study, we provide an in-depth investigation and analysis on the characteristics of channel-based transform waveforms and their differences from Fourier transform-based waveforms. Particularly, the basis functions of the recently proposed orthogonal transform division multiplexing (OTDM) waveform, which belongs to the category of channel-based transform waveforms, are comprehensively compared with the fixed exponential basis functions of orthogonal frequency division multiplexing (OFDM) waveform, which pertains to the class of Fourier transform-based waveforms. The obtained results show significant differences in the time and frequency characteristics of both classes of the waveforms. Also, the PAPR of OTDM is investigated and compared to OFDM. Then, a new effective technique, referred to as OTDM with edge subcarrier dedication (OTDM-ESD), is proposed for PAPR reduction by exploiting the special characteristics of the effective channel response in OTDM waveform. Simulation results show that the proposed OTDMESD technique not only reduces the PAPR remarkably, but also enhances the BER performance significantly.