基于广义空时干扰对齐的多用户MISO广播信道自由度分析  

DOF of multiuser MISO broadcasting channel based on generalizedspace-time interference alignment

作　　者：刘康 李赟 刘旭 石际 杨崇海 冯文江[2] LIU Kang;LI Yun;LIU Xu;SHI Ji;YANG Chonghai;FENG Wenjiang(Power Distribution and Control Center,Guizhou Power Grid Co.,Ltd.,Guiyang 550002,P.R.China;School of Microelectronics and Communication Engineering,Chongqing University,Chongqing 400044,P.R.China)

机构地区：[1]贵州电网有限责任公司电力调度控制中心,贵阳550002 [2]重庆大学微电子与通信工程学院,重庆400044

出　　处：《重庆邮电大学学报（自然科学版）》2020年第4期563-570,共8页Journal of Chongqing University of Posts and Telecommunications(Natural Science Edition)

基　　金：中国南方电网有限责任公司科技项目(GZKJXM20170825);重庆市前沿与应用基础研究计划项目(cstc2017jcyjBX0047)。

摘　　要：针对多用户MISO(multiple-input single-output)广播信道,提出一种广义空时干扰对齐方案。该方案利用非正交传输,在同一时隙将多用户的信号叠加发送,提高了频谱效率;利用当前和过期信道状态信息(channel state information,CSI)构造预编码矩阵,将不同时隙下的干扰信号对齐至同一维度,通过前后时隙的观测值消除用户间干扰,达到无干扰提取期望信号的目的。仿真结果表明,对于发射端配置M根天线的K用户MISO广播信道和干扰信道,系统自由度为KM/(1+M)。随着发射端天线数的增加,衰减因子M/(1+M)逼近1,可达自由度逼近外界K。This paper proposes a generalized space-time interference alignment(DSTIA)scheme for multiuser MISO broadcasting channels.In proposed scheme,multiuser user signals are superposed and coded in the same slot,non-orthogonal transmission is used to improve spectral efficiency.A precoding matrix is constructed according to the current and outdated channel state information(CSI),it can align the multiuser interference to the same dimension across time slot,thereby extracting the desired signal without interference.The conclusion shows that for the K user MISO broadcast channel and interference channel with M antennas at the transmitter,the sum-DoF is KM/(1+M).With the increase of the number of antennas at the transmitter,the DoF attenuation factor M/(1+M)≈1,and the sum-DoF is in the approximation to be the outer bound K.

关 键 词：MISO广播信道 空时干扰对齐 自由度 预编码 

分 类 号：TN929[电子电信—通信与信息系统]