High-performance OTFS transmitter on FPGA: A hybrid HLS/VHDL design

Rapid advances in high-speed vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications require innovative waveforms to address the challenges posed by mobility and the doubly dispersive nature of communication channels. Orthogonal Time Frequency Space (OTFS), a waveform operating in the delay-Doppler domain, offers enhanced robustness and performance under these conditions. This paper presents the implementation of an OTFS transmitter on a Field-Programmable Gate Array (FPGA), focusing on the ZedBoard platform. Two variants of the OTFS transmitter were developed and evaluated for data sizes of 16, 32, and 64 symbols. To benchmark their performance against conventional architectures, the implementations were re-evaluated on the 7vx485tfg1157-1 FPGA. The first variant achieved a throughput efficiency of 82.46 Tbps/W, utilizing 1,844 LUTs at an operating frequency of 147.8 MHz. The second variant demonstrated a higher throughput efficiency of 199.6 Tbps/W, consuming 3,094 LUTs with a maximum operating frequency of 149.52 MHz. These results highlight a significant improvement in performance while ensuring an optimal balance between resource utilization, latency, and throughput efficiency. This work underscores the potential of OTFS for real-time applications in future wireless networks, particularly in 6G communication scenarios.