A Generalized Matched Filter Framework for Cellular Massive MIMO Networks

“大规模MIMO”，也被称为“超大规模MIMO系统”，代表最近在无线通信中引入的一种新范例，被认为是即将到来的第五代移动通信系统所需的必要技术进步的重要候选者。大量的天线单元在给无线通信系统带来新的好处的同时，也带来了挑战。从信号处理的角度来看，大规模MIMO系统中的主要挑战之一是传输信道的有限相干时间的结果。在网络的相邻小区中同时服务的期望用户数通常超过每个专用于训练的相干块的信道接入数。换句话说，在不重新使用训练资源的情况下训练所需数目的信道似乎是不可能的，这因此引入了被称为所谓的“导频污染”现象的干扰。导频污染最终危及大规模MIMO范例，因为它降低了潜在的性能收益，即使对于大量的基站天线也是如此。该项目的重点是寻找新的概念来打破蜂窝海量MIMO网络中由于传输信道有限的相干时间而造成的“维度瓶颈”。我们将基于CSI的二阶统计量并考虑数值高效解的要求，对大规模MIMO网络中的波束形成和干扰协调的全部潜力进行研究。分析将从单细胞角度出发，并继续研究多细胞情景。相应的资源分配策略必须与目标波束形成和干扰协调方法联合设计，由于拟议的工作包将主要基于信道状态的“二阶统计量”，因此在该项目的过程中，信道协方差矩阵的获取显然将对目标解决方案起到至关重要的作用。

"Massive MIMO", also referred to as "Very-Large Scale MIMO Systems", stands for a recently introduced new paradigm in wireless communications considered to be an important candidate for the required technological progress necessary for the upcoming 5th generation of mobile communication systems. The huge number of antenna elements causes new benefits as well as challenges in wireless communication systems. One of the main challenges in Massive MIMO systems from the signal processing perspective is a consequence of the limited coherence time of the transmission channel. The desired number of users simultaneously served in neighboring cells of the network typically exceeds the number of channel accesses per coherence block dedicated for training. In other words, it appears to be impossible to train the desired number of channels without reusing training resources, which consequently introduces interference that is referred to as the so called "Pilot Contamination" phenomenon. Pilot Contamination ultimately jeopardizes the Massive MIMO paradigm as it degrades the potential performance gains even for an huge number of base station antennas. The focus of the proposed project is on finding novel concepts to break the "Dimensionality Bottleneck" in cellular Massive MIMO networks - imposed by the limited coherence time of the transmission channel. We will carry out a study of the full potential of beamforming and interference coordination in Massive MIMO networks based on Second-Order Statistics of the CSI and taking into account the requirement of numerically efficient solutions. The analysis will start from a single-cell perspective and continue with a study of multi-cell scenarios. The corresponding resource allocation strategies will have to be jointly designed with the targeted beamforming and interference coordination methods.Since the proposed work packages will be dominantly based on "Second-Order Statistics" of channel states, the acquisition of covariance matrices of channels will obviously play an essential role for the targeted solutions in the course of this project.