毫米波MIMO系统中的子天线阵列预编码算法研究

Research on precoding in millimeter wave MIMO system with antenna sub-array

在第五代无线通信技术的研究中,毫米波通信凭借着巨大的信道容量优势,得到了很多的关注和研究。而将毫米波通信技术应用到目前已经广泛使用的MIMO无线通信系统中,则可以更大幅度地增加信道容量。大天线阵列的应用,可以很好地缓解毫米波系统难以避免的路径损耗问题,但同时也增加了数字预编码器的硬件复杂度。为了简化复杂度,使用了一种子天线阵列的结构来替代全天线阵列结构,并同时在数字域和模拟域上来完成整个系统的预编码,进而提出了一种改进型的混合预编码算法,通过将复杂的信道容量求解问题分解为若干独立的子问题,并利用连续干扰消除的思想解决子天线阵列之间的干扰,以求得整个系统的最大信道容量问题。仿真结果表明提出的混合预编码算法在性能上十分接近最优算法,且复杂度大大降低。

In the research of the fifth generation wireless communication technology, due to the obvious advantages of the great channel capacity, millimeter wave communication has attracted more and more peopleg attention. In order to enhance the channel capacity, millimeter wave technology is applied in the MIMO system which has been widely used in wireless communication. Appli- cation of large antenna array can not only ease the problem of path loss in millimeter wave system, but also increase the number of precoder hardware complexity. In order to simplify the complexity, sub-array structure is applied to replace the full-array struc- ture, and the precoding of the whole system is completed both in the digital domain and analog domain. In addition, a modified hy- brid precoding algorithm is proposed in this paper. Firstly, decompose the complicated capacity optimization problem into a series of ones. Secondly, use the idea of solution of successive interference cancellation to obtain the maximum channel capacity of the system. The simulation results show that the proposed algorithm is very close to the optimal algorithm, and the complexity is greatly reduced.