基于大规模MIMO的空间和极化信道建模理论与方法研究

Large-scale MIMO (multiple-input multiple-output), with giant array size and multi-dimension array structure, has been widely considered as a key physical layer technique in future wireless communications. With regarding the large number of antennas, some new challenges and issues are arising, e.g. modeling the near-field effects in MIMO channel and the high computational complexity. To solve such issues, this project first plans to propose a novel channel model framework for a large-scale MIMO system by analyzing the effects of array size on the electromagnetic wave. Based on the proposed framework, we will formulate the near-field effects by constructing a new spatial vector and polarization matrix, in contrast to the traditional MIMO channel model. For fulfilling the channel model, we study the effective range of MIMO array of each cluster, and then convert the distribution of cluster in terms of the whole array to the distribution of cluster with respect to each antenna element. In sequence, we will propose a new method to obtain the spatial and polarization parameters for each antenna element. Furthermore, with regarding the trade-off between the model accuracy and the computational complexity, an application-oriented low complexity channel model will be derived based on the clustered delay line (CDL) model. Our project can provide necessary theoretical and technical supports for the future wireless communications.

大规模MIMO采用巨型阵列尺寸和多维阵列结构，能够有效提高无线频谱效率，是未来无线通信领域重要的物理层技术之一。但同时，大规模阵列也给MIMO信道建模带来近场效应、高计算复杂度等新挑战。针对这些挑战，课题首先通过分析阵列规模对电磁波传播的影响，建立大规模MIMO信道模型的基本框架；研究三维空间散射簇分布模型及散射簇在大规模阵列中的有效作用范围，探索根据散射簇分布将大规模阵列进行分解的新思路，进而提出针对局部阵列的空间、极化参数提取方法,解决大规模阵列给MIMO信道建模带来的近场效应问题。最后，寻求模型准确性和计算复杂度的最优折衷方案，形成面向应用的低复杂度信道模型，为基于大规模MIMO的下一代无线通信提供技术支撑。

目前国内外关于大规模MIMO的研究工作才刚刚起步，其无线信道建模存在诸多问题噬待解决。 本项目主要从传播环境参数提取及面向应用的信道参数处理两个方面，对大规模MIMO信道建模的准确性和计算复杂度相关难点问题展开研究，探索大尺寸、高维度MIMO的信道建模技术途径，为MIMO技术发展提供新的理论和方法。首先建立大规模MIMO信道模型统一框架，进而分析得到具体的模型参数，最后提出兼顾正确性和计算复杂度的折衷方案，形成面向对象的空间和极化信道模型。课题研究成果能够为基于大规模MIMO的未来无线通信系统提供有力支持。本项目在国内外重要期刊和会议上发表论文6篇，其中两篇属于中科院分区2区论文，以第一发明人身份申请国家发明专利1项，项目的研究成果为大规模MIMO的理论和实用化奠定了良好的技术基础。