空时编码多载波码分多址系统上行空时信道盲估计

Uplink Space-Time Channel Blind Estimation for Space-Time Coded Multicarrier Code Division Multiple Access Systems

针对当前空时编码系统利用训练序列求解信道信息将导致频谱资源浪费和系统用户容量下降这一问题,提出了宏蜂窝体制下基站使用均匀线阵空时编码多载波码分多址系统的上行空时信道盲估计算法.该算法构筑了蕴涵用户空时信道和波达方向的辅助矩阵,通过对该辅助矩阵进行特征分解得到了相应于每个用户的信号子空间,进而通过对该信号子空间进行奇异值分解实现了无需训练序列的空时信道的盲估计,节省了频带资源.仿真结果表明,该算法可以通过增加基站阵元数目使用户容量达到系统活动用户数的上限,并且信道估计的均方误差对用户数表现出鲁棒稳定性.

Current space-time coding systems estimate the channel state information by using of training sequences, which consume precious bandwidth and reduce the system user capacity. In view of this situation, an uplink space-time channel blind estimation algorithm is proposed for space-time coded multicarrier code division multiple access systems with uniform linear array at the base station in macrocell. An auxiliary matrix including both uplink space-time channels and directions of arrival is derived, on which the eigenvalue decomposition is performed to acquire the signal subspace corresponding to each user. Sequentially, the singular value decomposition is calculated on this signal subspace to estimate the space-time channels without training sequences, which saves bandwidth resources. Simulation results demonstrate that the algorithm can reach the maximum number of active users by increasing antenna array elements and the mean square error of channel estimations is robust against the number of users.