OTFS System-based on WFrFFT with Optimal Design Complexity

Orthogonal-time-frequency-space (OTFS) modulation is getting special attention for fifth-generation and beyond wireless communication due to its remarkable capability to establish stable communication links in high-speed environments. However, replacing present orthogonal-frequency-division-multiplexing (OFDM) communication systems with OTFS systems is a sophisticated and time-consuming task. Hence, an OTFS model is developed by employing discrete-fractional-Fourier-transform (DFrFT)-OFDM to improve bit-error-rate (BER) performance over the traditional OTFS systems. But DFrFT-based is limited by matrix multiplication which introduces additional computational complexity in the system. In this work, we propose a weighted fractional fast Fourier transform (WFrFFT)-based OTFS system. The complexity analysis shows that the proposed WFrFFT-based OTFS provides lower computation complexity than DFrFT-based OTFS system. Furthermore, the performance of the proposed system is also compared with that of the DFrFT-based OTFS and FFT-based OTFS systems.