中文摘要：

在基于有限反馈的多天线 MIMO 广播信道下，由信道量化误差带来的多用户干扰（MUI）会严重地降低系统性能。天线合并技术可以利用多接收天线提供的多维自由度有效地改善系统性能。该文针对最近被证明为最优的反馈资源分配策略，设计了一种线性天线合并算法，该算法在提高反馈精度和增强期望信号增益之间做出合理的折中，可使期望输出信噪干扰比（SINR）最大化。首先导出了线性合并器期望输出 SINR 的下界闭合表达式，然后利用这个表达式得到使输出SINR最大化的线性合并器。仿真表明该线性合并算法与已有算法相比具有明显的性能提升。

英文摘要：

MultiUser Interference （MUI） caused by channel quantization error degrades the performance of the limited feedback-based multiuser Multiple-Input Multiple-Output （MIMO） systems. Antenna combining techniques can effectively improve the system performance with the additional dimension of freedom. In this paper, a linear antenna combiner is proposed for the feedback overhead allocation strategy which is proved to be the optimal scheme. First, the closed-form lower bound of each user’s expected post-combining Signal-to-Interference-plus-Noise Ratio （SINR） is derived. Then, using this bound expression, the proposed combiner is obtained which aims to maximize the expected post-combining SINR. Monte Carlo simulations show that the proposed combiner achieves better performance compared with the existing antenna combining algorithms.