基于压缩感知的STAR-RIS辅助毫米波系统信道估计

Channel estimation for STAR-RIS-assisted millimeter wave system based on compressed sensing

一种可同时透射和反射的可重构智能表面(simultaneously transmitting and reflecting reconfigurable intelligent surface,STAR-RIS)可以同时辅助位于其两侧用户的无线通信。针对STAR-RIS辅助下的双用户毫米波通信系统的上行链路信道估计问题进行了研究,并对两用户在角度域的联合稀疏特性进行了探究。基于级联信道的联合稀疏特性和压缩感知理论,将级联信道估计问题转化为稀疏信号恢复问题,并提出了一种位置判决正交匹配追踪(position-judgment orthogonal matching pursuit,PJ-OMP)算法以减少导频开销。仿真结果显示,与传统的正交匹配追踪(orthogonal matching pursuit,OMP)算法相比,所提出的算法能够减少信道估计的导频开销,即使在某一侧用户所分配的能量较少时也能够准确地估计信道。

A simultaneously transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)can simultaneously assist wireless communication for users located on both sides of the STAR-RIS.The uplink channel estimation problem of a dual-user millimeter wave communication system assisted by STAR-RIS is studied,and the joint sparse characteristic of the two users in the angle domain is explored.Based on the joint sparse characteristic of cascaded channels and compressed sensing theory,the cascaded channel estimation problem is transformed into a sparse signal recovery problem,and a position-judgment orthogonal matching purity(PJ-OMP)algorithm is proposed to reduce pilot overhead.Simulation results show that compared with the traditional orthogonal matching pursuit(OMP)algorithm,the proposed method can reduce pilot overhead in the channel estimation process,and can accurately estimate the channel even when the energy allocated to the user on one side is less.