Integrated Sensing and Communications Waveform Design for OTFS and FTN Fusion

In this letter, we propose an Integrated Sensing and Communications (ISAC) waveform design method based on the fusion of Orthogonal Time Frequency Space (OTFS) and Faster-Than-Nyquist (FTN). The objective is to maximize the communication data transmission rate while minimizing the sensing performance impact on the target parameter estimation. We first map the FTN symbols to OTFS waveform time domain for realizing symbol spacing compression and transmit them in time-varying channels. Then, an equalizer based on the Minimum Mean Square Error (MMSE) algorithm is used to eliminate the interference generated by the FTN. Simulation results show taking into account the system bit-error rate, the proposed method achieves an increase in the throughput as well as an improvement in the distance and velocity estimation of the target compared to the existing methods.