多用户MIMO下行链路通信系统必须设计合适的预编码方案来抑制多用户间的共信道干扰. 该文提出一种基于连续迭代优化信号泄漏噪声比最大准则的预编码方法.利用已知用户未使用的子信道空间增大其他用户的预编码空间自由度，降低干扰泄漏，并用迭代法进一步抑制多用户干扰，提高接收端信干比.该方法仅在发射端使用用户的信道信息优化与编码矩阵，不需要基站与用户协作，接收端可自由选择检测算法，且不会增加系统开销.仿真结果表明，所提方法取得了比原SLNR方法更好的系统性能，且具有较快的收敛速度，实用性较强.

In the downlink of a multi-user MIMO system, an appropriate pre-coding algorithm is needed to suppress co-channel interference. Based on the criterion of maximum signal-to-leakage-and-noise-ratio (SLNR), a successive iterative optimization pre-coding scheme is proposed. The method uses the unused subspace of known users to improve the space degree-of-freedom of the other users, and reduces the leakage. An iterative optimal method is applied to further suppress multi-user interference (MUI) and improve the signal-to-interference-and-noise-ratio (SINR) at the receiver. The proposed scheme only makes use of the channel information of the users at the transmitter to optimize the pre-coding matrix without collaboration between the base stations and the users. Any detection algorithm can be selected at the receiver without increasing the system overhead. Simulation results show that the proposed scheme has better performance and faster convergence than the original SLNR algorithm, and therefore is suitable for practical applications.