西安电子科技大学学报（自然科学版）2025，Vol.52Issue(5)：59-71,13.DOI:10.19665/j.issn1001-2400.20250602
导频辅助的AFDM系统符号同步和信道估计技术
Pilot-aided symbol synchronization and channel estimation techniques for AFDM systems
摘要
Abstract
As a multicarrier modulation technique proposed for high-speed mobile scenarios,AFDM can completely separate each path of the doubly selective channel,achieving full time and frequency diversity gains.It is a strong candidate waveform for the physical layer of future mobile communications.However,current research achievements on symbol synchronization for AFDM systems are very limited,and traditional synchronization algorithms struggle to achieve a good performance in complex doubly selective channels.Aiming at this problem,this paper proposes a coarse-fine two-stage synchronization algorithm suitable for doubly selective channels.By relying on fine synchronization performed in the discrete affine Fourier transform(DAFT)domain to correct errors from coarse synchronization,a high synchronization accuracy is obtained under doubly selective channels,on the basis of which this paper combines the repeated multi-segment pilot structure required for coarse synchronization,and jointly designs fine synchronization with channel delay-Doppler shift estimation,thus saving pilot overhead.Finally,the channel complex gain information is obtained using the LS estimation algorithm,thereby realizing symbol synchronization and channel estimation for the AFDM system.Simulation results show that the algorithm has a high synchronization accuracy and an accurate channel estimation in time-frequency dual selection channels,and that the requirement for pilot energy in channel estimation is significantly reduced,demonstrating its good adaptability and application prospects in time-frequency dual selection channel environments.关键词
AFDM/同步/信道估计/多载波调制Key words
AFDM/synchronization/channel estimation/multicarrier modulation分类
信息技术与安全科学引用本文复制引用
郭林,郭伟,王勇超..导频辅助的AFDM系统符号同步和信道估计技术[J].西安电子科技大学学报（自然科学版）,2025,52(5):59-71,13.基金项目
国家自然科学基金青年项目(62201425) （62201425）
陕西省科技计划项目(2020ZDLGY15-01,2024PT-ZCK-11) （2020ZDLGY15-01,2024PT-ZCK-11）
国家自然科学基金(62271371) （62271371）
重庆市自然科学基金创新发展联合基金(CSTB2024NSCQ-LZX0162) （CSTB2024NSCQ-LZX0162）
