Interference Suppression Schemes Using Limited Feedback Precoding In Multi-cell Systems

There has been great growth in wireless communications in the last few decades and high spectral efficiency is still a pressing demand nowadays. Multiple-input Multiple-output (MIMO) is by far one of the most promising existing wireless communication technologies. However, because of the interference from adjacent cells which use the same frequency band, the spectral efficiency is still limited although using MIMO in cellular systems. So in order to obtain the capacity gain, some potent interference suppression method should be used in wireless cellular systems.The techniques of precoding including some linear and nonlinear precoding schemes are quite effective to mitigate adjacent interference. There are different precoding matrix designing optimization criterions which may result in different performance. Signal-to-interference-and-noise ratio(SINR) maximization is one of the most common criterions. But the optimal solution of SINR maximization is usually hard to obtain with coupled variables problems in multi-cell scenario. So in plenty of investigation some suboptimal methods are studied, thereinto one of the most popular is virtual signal-to-interference-and-noise ratio(VSINR) based precoding. In this paper, we propose two novel precoding schemes based on VSINR in multi-cell scenario. One of them is combined with cooperative power allocation, the other one is combined with TH precoding. In these two schemes, all BSs precode seperately instead of sharing any channel state information.This paper introduces the structure of multi-cell scenario and intercell interference first. Then we describe the technology of precoding to suppress intercell interference in the downlink communication and simulate the proposed schemes at last.