Low earth orbit(LEO)satellite communication which can provide global wireless ser-vice plays a critical role in the future wireless communication networks.However,due to the high speed of satellite motion,numerous nar...Low earth orbit(LEO)satellite communication which can provide global wireless ser-vice plays a critical role in the future wireless communication networks.However,due to the high speed of satellite motion,numerous narrow beams,and complex satellite-terrestrial channels,the initial access between the LEO satellites and user terminals(UEs)becomes more complicated.To establish a stable link,a beam search is required between the satellite and the UE.However,tradi-tional beam search methods(e.g.,exhaustive search)have high time complexity which is not suit-able in high-speed scenarios.Therefore,in this paper,a sensing-aided hierarchical beam search method is proposed,which is performed in two stages.In the first stage,wide beam scanning is per-formed to find the optimal angular range.In the second stage,after determining the directions of narrow beams via sensing the direction of arrival(DOA)of satellite signals,the narrow beams gen-erated at estimated directions are used to sweep the satellite beams.This method can help fast beam alignment and obtain high beam search accuracy,which is verified by simulation results.Moreover,we analyze the gain of beam alignment from the two-stage beam search method.展开更多
基金supported in part by Chongqing Natural Science Foundation Innovation and Development Joint Fund(No.CSTB2024NSCQ-LMX0024)in part by Shanghai Natu-ral Science Foundation(No.24ZR1421800)。
文摘Low earth orbit(LEO)satellite communication which can provide global wireless ser-vice plays a critical role in the future wireless communication networks.However,due to the high speed of satellite motion,numerous narrow beams,and complex satellite-terrestrial channels,the initial access between the LEO satellites and user terminals(UEs)becomes more complicated.To establish a stable link,a beam search is required between the satellite and the UE.However,tradi-tional beam search methods(e.g.,exhaustive search)have high time complexity which is not suit-able in high-speed scenarios.Therefore,in this paper,a sensing-aided hierarchical beam search method is proposed,which is performed in two stages.In the first stage,wide beam scanning is per-formed to find the optimal angular range.In the second stage,after determining the directions of narrow beams via sensing the direction of arrival(DOA)of satellite signals,the narrow beams gen-erated at estimated directions are used to sweep the satellite beams.This method can help fast beam alignment and obtain high beam search accuracy,which is verified by simulation results.Moreover,we analyze the gain of beam alignment from the two-stage beam search method.
