基于Weichselberger模型的3D MIMO信道建模研究

3D MIMO(Three Dimension Multiple Input Multiple Output)技术是下一代通信系统(5G)关键的技术之一。为了更好地评估3D MIMO通信系统的性能,需要建立一种准确的3D MIMO信道模型。在现有的3D MIMO信道模型中,3D Kronecker模型由于其简单性而得到广泛应用。但3D Kronecker模型假设收发两端是不相关的,与实际信道特性不符。为解决该问题,本文在WINNER II中2D信道模型的基础上引入仰角维度,建立3D MIMO信道模型,并推导收发两端的相关矩阵,通过分解收发两端相关矩阵构建3D Weichselberger模型。本文着重分析六种典型场景下3D Weichselberger模型的空间耦合矩阵,并通过理论推导分析各种场景下的3D MIMO信道特征,同时推导出3D Weichselberger模型的互信息上限的表达式。仿真结果显示,相对于3D Kronecker模型,3D Weichselberger模型能更准确地描述3D信道的传播特征。

Linear Precoder Design for Correlated Rician Fading Channel Under Imperfect CSI

In this paper,we have modeled a linear precoder for indoor multiuser multiple input multiple output(MU-MIMO)system with imperfect channel state information(CSI)at transmitter.The Rician channel is presumed to be mutually coupled and spatially,temporarily correlated.The imperfection with CSI is primarily due to the channel estimation error at receiver and feedback delay amidst the receiver and transmitter in CSI transmission.Along with,the insufficient spacing between the antenna at transmitter and receiver persuades mutual coupling(MC)among the array elements.In addition,the MIMO channel is presumed to be jointly correlated(Weichselberger correlation model).When we look back on the existing precoder design,it considered spatial correlation alone disregarding joint correlation of antenna array elements.With all above assumption,we have designed a linear precoder which minimizes mean squared error(MSE)subjected to total transmit power constraint for MUMIMO system.The simulation results proven that proposed precoder shows substantial enhancement in bit error rate(BER)performance in comparison with the existing technique.The mathematical analysis corroborates the simulation results.