Efficient FPGA Implementation of SISO-OTFS Modem for Aircraft Communications in High-Doppler Scenarios

Orthogonal Time Frequency Space modulation is an advanced technique in wireless communications, designed to work in Linearly Time-Varying channels. This paper outlines a low-complexity, discrete-time single-input-single-output (SISO) OTFS system implementation. We also detail a block-wise OTFS receiver that utilizes the OTFS transmission matrix structure. The receiver features an iterative approach, integrating a least squares minimum residual-based channel equalizer, a reliability-based symbol detector, and an interference eliminator. This method is designed to quickly converge by leveraging the channel matrix’s sparsity, significantly reducing detection errors while maintaining lower complexity. This enhances performance in high mobility dynamic communication environments such as Aircraft communications.