密集小小区莱斯衰落CoMP预编码及分时反馈的设计

Precoding codebook and time-division feedback design for Small Cell CoMP in Rician channel

密集小小区场景存在很强的视线传输(line-of-sight,LOS)成份,传统基于瑞利衰落的多点协作预编码码本性能将受到限制,同时密集小小区环境下非视线传输(non-line-of-sight,NLOS)成分将更加复杂需要频繁地进行反馈。因此提出一种针对密集小小区莱斯信道的码本设计方案,充分利用LOS和NLOS成分,并结合慢速移动场景的信道特点采用差分码本的形式,在不增加码本空间的基础上提高了实际的码本量化能力。同时设计了一种长短周期相结合的分时反馈方案,对不同莱斯因子的信道场景提供更灵活的支持。

Compared with the traditional cellular network, Small Cell has strong line-of-sight （LOS） com- ponents caused by the shorter distance. The non-line of-sight （NLOS） components in Small Cell will be much more complex,which needs frequent feedback, because of the increasing number of access points. The perfor- mance of traditional Rayleigh based coordinated multipoint transmission （CoMP） precoding mechanism will be- come worse in Small Cell. Therefore,a Rician-based CoMP precoding eodebook for Small Cell is proposed. It takes both of LOS and NLOS into consideration and uses a form of differential codebook based on the channel characteristics in low-mobility scene, which can improve the practical codebook quantitative ability without in- creasing the codebook size. A time-division feedback strategy combining long-term and short-term preeoding matrix indicator is proposed to provide a flexible support to the channels of different Rician factors.