An hybrid framework OTFS OFDM based on mobile speed estimation

Abstract: The Future wireless communication systems face the challenging task of simultaneously providing high quality of service (QoS) and broadband data transmission, while also minimizing power consumption, latency, and system complexity. Although Orthogonal Frequency Division Multiplexing OFDM has been widely adopted in 4G and 5G systems, it struggles to cope with the significant delay and Doppler spread in high mobility scenarios. To address these challenges, a novel waveform called Orthogonal Time Frequency Space OTFS has emerged, aiming to outperform OFDM by closely aligning signals with the channel behaviour. In this paper, we propose a switching strategy that empowers operators to select the most appropriate waveform based on the estimated speed of the mobile user. This strategy enables the base station to dynamically choose the waveform that best suits the mobile users speed. Additionally, we suggest integrating an Integrated Sensing and Communication radar for accurate Doppler estimation, providing precise information to aid in waveform selection. By leveraging the switching strategy and harnessing the Doppler estimation capabilities of an ISAC radar, our proposed approach aims to enhance the performance of wireless communication systems in scenarios of high mobility. Considering the complexity of waveform processing, we introduce an optimized hybrid system that combines OTFS and OFDM, resulting in reduced complexity while still retaining performance benefits. This hybrid system presents a promising solution for improving the performance of wireless communication systems in scenarios with a high mobility. The simulation results validate the effectiveness of our approach, demonstrating its potential advantages for future wireless communication systems. The effectiveness of the proposed approach is validated by simulation results as it will be shown.