Beyond Legacy OFDM: A Mobility-Adaptive Multi-Gear Framework for 6G

TL;DR

This paper proposes GS-OFDM, a flexible framework for 6G that adaptively switches between different OFDM gears based on user mobility, improving performance in high-mobility scenarios.

Contribution

It introduces gear-switching OFDM (GS-OFDM), enabling adaptive selection among three gears to enhance 6G communication robustness and efficiency.

Findings

Adaptive gear switching improves throughput in high-mobility scenarios.

GS-OFDM unifies legacy OFDM and delay-Doppler processing.

The framework offers a pathway for future 6G waveform design.

Abstract

While Third Generation Partnership Project (3GPP) has confirmed orthogonal frequency division multiplexing (OFDM) as the baseline waveform for sixth-generation (6G), its performance is severely compromised in the high-mobility scenarios envisioned for 6G. Building upon the GEARBOX-PHY vision, we present gear-switching OFDM (GS-OFDM): a unified framework in which the base station (BS) adaptively selects among three gears, ranging from legacy OFDM to delay-Doppler domain processing based on the channel mobility conditions experienced by the user equipments (UEs). We illustrate the benefit of adaptive gear switching for communication throughput and, finally, we conclude with an outlook on research challenges and opportunities.