一种基于斜投影的预编码技术研究

摘要

现有的MU-MIMO系统一般采用基于正交投影的方法来处理用户信道,即通过增大用户最小的信道增益来最大化最差一路性能,然而这种方法在组建并行信道时减少了信道增益.为了减少正交投影的方法带来的增益损失,进一步提高系统容量,在研究了现有的预编码方案以及斜投影的原理之后,结合块对角化预编码和几何均值分解,提出了一种新的基于斜投影的线性预编码算法,建立了基于斜投影的预编码的系统模型,并在此系统模型上利用注水功率算法推导出了系统容量的闭式表达式.仿真结果表明,在低信噪比的情况下该方案可以获得比现有正交投影方案更高的系统总容量.%In current MU-MIMO systems orthogonal projection method is generally emploied in the user channel to maximize the performance of the worst channel by increasing the minimum channel gain. We introduced the research of linear preceding in multi-user MIMO system and the mathematical preliminaries of oblique projection; and then imple mented oblique projection technique into BD-GMD system; proposed a novel linear precoding based on oblique projection to reduce the gain loss caused by the orthogonal projection method and further increase the system capacity. System model of this precoding algorithm is in detail; and derive out the closed-form expression of system capacity by imple menting water-filling power allocation algorithm into the modeL Simulation shows that in low SNR the proposed scheme can obtain higher system capacity than the orthogonal projection schema.