Performance Analysis of Emerging Waveforms for 6G Wireless Communications

Next-generation wireless communication systems (beyond 5G/6G) are envisioned to support high-mobility scenarios. The performance of traditional multicarrier waveforms such as orthogonal frequency division multiplexing (OFDM) deteriorates dramatically because of the loss of orthogonality between the subcarriers induced by severe Doppler frequency shifts. many emerging multi-carrier waveforms have been introduced to enhance performance in high-mobility scenarios. This paper focuses on the three promising waveforms which are (1) orthogonal time frequency space (OTFS) modulation is a 2D modulation technique designed in the delay-Doppler domain, (2) orthogonal time sequency multiplexing (OTSM) is a single carrier modulation scheme that places information symbols in the delay-sequency domain followed by a cascade of time-division multiplexing (TDM) and Walsh-Hadamard sequence multiplexing, and orthogonal chirp division multiplexing (OCDM) is a new multi-carrier scheme based on the chirp spread spectrum (CSS) and shown to be more robust to interference caused by insufficient guard intervals. In this paper, we aim to present a comprehensive overview of these candidates’ waveforms techniques. We also analyze their performances of them over doubly dispersive channels. The simulation results show that the candidates waveforms techniques outperform OFDM over fast time-varying channels. we finally give the candidate waveform suggestions.