Multi-user joint RIS channel estimation based on ADMM
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NETL
NSTL
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针对智能反射面(reconfigurable intelligent surface,RIS)辅助的毫米波通信系统中传统信道估计方案导频开销过高、计算复杂度较大的问题,提出了一种基于多用户联合场景的交替方向乘子法(alternating direction method of multipliers,ADMM)信道估计方案.首先,利用不同用户级联信道存在公共BS-RIS部分,估计出用户信号的公共子空间并进行投影,有效减弱了噪声的影响.其次,考虑多用户级联信道的相关性和稀疏性,构建了稀疏级联信道矩阵和公共缩放因子矩阵的优化问题.对于该非凸联合优化问题,采用ADMM算法,交替优化估计稀疏矩阵和公共缩放因子矩阵.仿真结果表明,与现有方法相比,提出的基于多用户联合的ADMM信道估计方案导频开销将减少约50%.
Addressing the challenges of high pilot overhead and computational complexity in traditional channel estima-tion methods for millimeter-wave communication systems aided by reconfigurable intelligent surfaces(RIS),a novel channel estimation algorithm based on the alternating direction method of multipliers(ADMM)for multi-user joint sce-narios was proposed.Firstly,leveraging the shared base station(BS)-RIS component within the cascaded channels of different users,the common subspace of user signals was estimated and projected to effectively mitigate noise interfer-ence.Secondly,considering the correlation and sparsity of multi-user cascaded channels,an optimization problem for the sparse cascaded channel matrix and common scaling factor matrix was formulated.To solve this non-convex joint optimization problem,the ADMM algorithm was employed to alternately optimize the sparse matrix and the common scaling factor matrix.Simulation results demonstrate that,compared to existing methods,the proposed ADMM-based channel estimation algorithm for multi-user joint scenarios reduces pilot overhead by approximately 50%.
massive MIMOreconfigurable intelligent surfacechannel estimationalternating direction method of multipliers
NETL
NSTL
万方数据
