Performance Analysis of Feedback Reduction inMIMO System with Spatial Heterogeneity

• Main Authors: Wei-Hsiang Wang, 汪煒翔
• Other Authors: Hsuan-Jung Su
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/3gqx95

碩士 === 國立臺灣大學 === 電信工程學研究所 === 105 === In multiuser multiple-input multiple-output (MU-MIMO) downlink broad-cast channel, several users can be simultaneously served through space division multiple access (SDMA), which exploits the multiplexing gain of MIMO system. To improve the system sum rate, users feedback their channel state information (CSI) to help the base station (BS) to schedule those with the best channel conditions. This incurs a large aggregate feedback bandwidth growing linearly with the number of users. There are already several studies investigating the threshold-based feedback schemes to reduce the amount of feedback. However, they are limited to the homogeneous cases. In this thesis, we develop the realistic and general model for the MU-MIMO opportunistic feedback scheme, where users are uniformly distributed in the cell. With this model, we analyze the sum rate growth as the number of users is in nite and extend the feedback reduction method to the heterogeneous network considering the fairness problem with CDF scheduling. It provides the fair channel access time fraction and tractable analysis. For homogeneous network, the closed form expression of sum rate/rate loss(due to the outage event, i.e. no one feedback CSI), with nite users is obtained. Also, we analyze the dual problem, MU-MIMO opportunistic feedback scheme in multicast channel with the proposed model, and the closed form expression of homogeneous case is also derived.