X-structured Precoding for Multiuser MIMO Systems

• Main Authors: Lo, Wan-Chi, 羅婉綺
• Other Authors: Wu, Wen-Rong
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/02474400293605282660

碩士 === 國立交通大學 === 電信工程研究所 === 101 === Multiuser multiple-input-multiple-output (MU-MIMO) systems have been extensively studied recently. The main problem in the system is that the transmitted signal from a basestation to one user is interfered by the signals to other users. MU-MIMO precoding has been proposed as an effective way to solve the problem. In the approach, the interference between the different users is pre-canceled at the transmitter. Existing precoders mainly designed with zero-forcing (ZF) or minimum mean-square-error (MMSE) criteria and the performance is limited. This thesis aims to investigate MU-MIMO precoding with the maximum likelihood (ML) criterion. We propose using a newly developed X-structured precoding scheme in the MU-MIMO system. First, we use block diagonal schemes to cancel the multi-user interference such that the MU-MIMO system can be transferred to a set of parallel single-user MIMO (SU-MIMO) systems. Then, we conduct the X-structured precoding for each SU-MIMO system, and power allocating for all SU-MIMO systems. Numerical results show that the proposed method significantly outperforms the existing MU-MIMO precoding methods.