中文摘要：

针对现有多天线机会多播调度方案中存在的问题，提出一种半动态机会多播调度算法，将多天线有限反馈的码字选择方案与机会多播调度方案相结合，解决了现有码字选择中的NP-hard问题，提高了系统容量。另外还提出了一种降低反馈量的次优方案。仿真显示，该方案改善了现有多播调度方案的次优算法，同时在损失少量系统容量的情况下大大降低了系统反馈量。

英文摘要：

In previous works on MIMO multicast transmit precoding design, the authors either assumed perfect trans- mitter-side channel state information （CSIT） or special channel conditions that facilitate precoding design with imper- fect CSIT. In this paper, we combine transmit precoding design with Opportunistic Multicast Scheduling （OMS） and a semi-dynamic scheduling algorithm is proposed to adjust the user selection ratio adaptively in each transmission. Simulations show that the proposed algorithm could significantly improve the average system throughput. Finally, we propose a feedback reduction scheme and study the tradeoff between feedback cost and performance loss.