A OTFS System Based Weighted Fractional Fourier Transform

The use of the Orthogonal-Time-Frequency-Space scheme in wireless communication has been extensively studied due to its exceptional reliability in establishing communication links in high-speed stations. Compared with OFDM modulation, in high-speed communication, the channel behavior becomes more dynamic in the Time Frequency (TF) domain. The channel used in OTFS modulation remains invariant in the Delay-Doppler (DD) domain, which is a useful tool for resolving issues with frequency selective channels. Given that the OFDM scheme based on the Fractional Fourier Transform (FrFT) has proven to be better than traditional OFDM schemes. We choose to integrate the FrFT-based OFDM modulation to improve the performance of the OTFS modulation. The 4-Weighted Fractional Fourier Trans-form (4-WFrFT) is a variation of the FrFT, which is regarded as a generalized form of the Fourier Transform. Thus, in order to evaluate the OTFS system's performance, we have decided to use 4-WFrFT-based OFDM in this paper.We determined the fixed alpha value to be 0.95 and compared MMSE and ZF equalizers to evaluate the performance of the OTFS system. In particular, we assessed the performance in terms of Bit Error Rate (BER) for 4-QAM and 16-QAM modulations.