移动环境下Massive MIMO高性能传输理论与技术

Massive MIMO（大规模多输入多输出系统）是5G移动通信系统物理层最核心的技术之一。它通过在基站侧部署大量天线使得系统频谱效率和能量效率都相比传统MIMO有极大的提升。然而在5G第一阶段部署中，一个学术界没有预见到的巨大挑战——移动性问题被发现，并成为当前Massive MIMO高速传输中的最大痛点。测试团队发现在中高速移动环境下Massive MIMO的频谱效率相对于低速环境下降50%甚至80%以上。这个问题源于Massive MIMO对信道信息准确度的高度敏感性。本项目拟围绕信道过时与有限反馈下的信道信息获取机制、基于信道统计信息及多域分集技术的鲁棒性传输、隐逝波对全息MIMO作用机理这三大科学问题为核心开展研究，旨在打破Massive MIMO中的移动性诅咒，也为解决未来移动通信系统中的超大规模MIMO、全息MIMO、太赫兹通信中必然会遇到的移动性问题提供关键理论与技术支持。

Massive MIMO (massive multiple input multiple output system) is one of the key technologies for the physical layer of the fifth generation (5G) mobile communication systems. By deploying a large number of antennas on the base station, massive MIMO leads to unprecedented improvements of spectral efficiency and energy efficiency compared to traditional MIMO with fewer antennas. However, during the initial phase of 5G deployment, a severe problem, not foreseen by theoretical papers in academia, arises as the biggest challenge for high-performance transmission of massive MIMO. It is known as the mobility problem. In fact, testing team of industry discovered that the spectral efficiency of massive MIMO in medium- to high-speed mobile environments drops around 50%~80% compared to the low-mobility environments. This problem is rooted in the acute sensitivity of massive MIMO to its channel information. In order to break this curse of mobility, this application will focus on three major scientific problems: channel acquisition mechanism under channel aging and limited feedback, robust transmission based on channel statistics and multi-domain diversity technology, and the mechanism of the effect of evanescent waves on holographic MIMO. This project will also provide key theoretical and technical supports for solving the problems of mobility that will be encountered in ultra-large MIMO, holographic MIMO, and terahertz communications in future mobile communication systems.