Abstract:

Compared with the traditional cellular network, Small Cell has strong line-of-sight (LOS) components 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 performance of traditional Rayleigh based coordinated multipoint transmission (CoMP) precoding mechanism will become worse in Small Cell. Therefore,a Rician based CoMP precoding codebook 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 increasing the codebook size. A timedivision feedback strategy combining long term and short term precoding matrix indicator is proposed to provide a flexible support to the channels of different Rician factors.