基于四阶累积量的MIMO信道及其相关性的联合估计

MIMO技术一直受到人们的广泛关注,并被广泛采用于各种移动通信系统的标准化协议中.在此系统中用到的分集合并和空时解码技术都需要以准确估计的信道状态信息为前提条件,以往的信道估计都是在MIMO系统子信道间是非相关的假设下进行的.事实上,由于天线之间距离的限制和传播路径散射体的不充分,子信道之间常常存在一定的相关性,常称为空间相关.另外,在信道估计、天线选择和自适应调制等方面需要已知(估计)这一参数.但是,要精确估计信道的相关性非常困难,到目前为止,这一问题没有得到很好的解决,以至于在大部分关于信道估计的文献中都是预先假定已知信道的相关特性.本文运用四阶累积量理论对MIMO信道及其相关矩阵进行了估计.仿真结果表明,本文所提出的方法具有较高的估计精度.

Joint estimation of MIMO channel and correlation based on the forth order cumulant

Up to be the concept of multiple-input multiple-output(MIMO) system has drawn a lot of attention, up to be listed as a potential improvement of mobile communication systems in standardization forums. Channel state information has to be estimated for diversity combining or space-time decoding. Former work on channel estimation always under the assumption that MIMO channels are independent and identically distributed (i.i.d.).Actually, there exists spatial correlation among channels corresponding to different pairs of transmit and receive antennas. Otherwise, we can make use of this spatial correlation to improve the performance of chosen antenna, adaptive modulation, adaptive power location and so on. In the former work, the channel correlation matrix which was hard to observe in practice environment was given directly. In this paper, we estimate the MIMO channel using the forth order cumulant and simultaneity estimate the spatial correlation matrix.