中文摘要：

研究多小区MU-MIMO中的预编码设计.通过扩展单小区块对角化预编码将泄漏到邻小区的干扰纳入考虑范围,根据信道投射的块对角化预编码和发送端提供的额外自由度,以最大化信漏比为原则对发送信号进行预处理.在目标用户信号和泄露干扰之间取得一个折中以实现泄露干扰抑制的目的,同时在小区内用户间进行子空间迫零以消除用户间干扰,从而降低小区干扰对多用户MIMO系统的不利影响.相较于经典的泄漏干扰迫零算法,可以灵活地调整用于小区间干扰抑制的自由度,平衡抑制干扰与提升系统容量的矛盾关系.理论分析和仿真均证明,该方法能有效抑制小区间干扰,提升系统容量,在相同干扰的条件下甚至可以成倍增加容量,且不用改变现有通信系统的拓扑结构,实现复杂度较低.

英文摘要：

In this paper,an optimal precoding is designed for multi-cell multi-user MIMO networks.It is proposed to expand a block diagonalization method of single cell to the multi-cell situation.Considering interference leakage to out-of-cell users,a channel projection based block diagonalization （BD） method is used in designing the precoding.Using the extra-space freedom degree offered on the transmitting side,the transmit signal is preprocessed with a cell-based signal-to-leakage-plus-noise ratio （SLNR） maximization criterion,which can compromise the target user signal and leakage interference to suppressed interference.Moreover,a traditional subspace zero forcing procedure is proceeded to mitigate the interference among intra-cell users.Thus,negative factors of the inter-cell interference for the multi-user MIMO system can be suppressed.Compared to the classical interference leakage zero forcing algorithm,it can flexibly adjust the freedom for inter-cell interference suppression,balance relationship between interference suppression and system capacity enhancement.Moreover,under the same interference,the capacity can be doubled.Both theoretical analysis and simulation indicate that the proposed methods can efficiently suppress interference while keeping low complexity without changing topology of the current systems.