采用大规模分布式基站天线的移动通信系统容量分析与性能优化

With the rapid development of mobile Internet in the past years, how to support high-speed data transmission for massive users within limited spectrum has become the most urgent issue in the next-generation mobile communication system design. The distributed antenna system (DAS) has become one of the most promising candidate thanks to its great potential in high spectrum efficiency and low transmission power. This project will study the mobile communication system where a massive number of distributed BS antennas are adopted. With traditional cellular structure, the cell-edge users in a DAS experience significant performance loss due to the severe inter-cell interference. To settle this issue, we will adopt a user-centric cellular structure in this project, where the surrounding BS antennas of each user form a virtual cell and provide service to its corresponding user. In this project, we will study the Shannon capacity limit of the downlink channel of a DAS with virtual cell structure where a massive number of BS antennas are employed, and focus on its performance evaluation and practical application. This project mainly includes three parts, which are the capacity analysis, power allocation scheme, and precoding scheme, and tries to solve three key science issues, which are how to analyze the downlink channel capacity, how to balance the capacity of different users, and how to eliminate the interference from overlapping areas of different virtual cells. This project will lay solid foundation for the application of massive DAS in mobile communication systems.

随着移动互联网的迅速发展，下一代移动通信系统如何在有限的频谱中实现大量用户的高速数据传输是亟待解决的问题。分布式天线系统以其高频谱效率、低发射功率的优势成为下一代移动通信系统有竞争力的解决方案之一。本项目面向采用大规模分布式基站天线的移动通信系统，针对采用传统蜂窝小区结构的分布式天线系统中小区边缘用户因小区间干扰导致性能急剧恶化这一特点，创新性的采用基于用户位置的虚拟小区结构，即选取各用户邻近的分布式天线组成各自的虚拟小区。本项目以下行信道的香农容量限为研究对象，将从容量性能评价和应用技术方面进行前瞻性基础研究。本项目主要包含大规模分布式天线系统的容量分析、功率分配策略和预编码策略三项研究内容，旨在解决如何分析下行信道容量性能、如何实现用户间容量性能的平衡、如何消除有交叠区域的虚拟小区对用户的干扰三个关键科学问题，将为大规模分布式天线系统在移动通信系统中的应用打下坚实的理论基础。

随着移动互联网的迅速发展，下一代移动通信系统如何在有限的频谱中实现大量用户的高速数据传输是亟待解决的问题。分布式天线系统以其高频谱效率、低发射功率的优势成为下一代移动通信系统有竞争力的解决方案之一。本项目面向采用大规模分布式基站天线的移动通信系统，针对采用传统蜂窝小区结构的分布式天线系统中小区边缘用户因小区间干扰导致性能急剧恶化这一特点，采用基于用户位置的虚拟小区结构，即选取各用户邻近的分布式天线组成各自的虚拟小区。本项目以下行信道的香农容量限为研究对象，从容量分析、功率分配策略和预编码策略三个方面展开研究。.在容量分析方面，本项目对单用户和多用户分布式天线系统的下行信道容量进行了分析，获得了平均容量下界的解析解。在此基础上，对采用虚拟小区的分布式天线系统下行信道干扰性能进行了建模和分析，并研究了其下行容量性能。在功率分配策略方面，本项目获得了采用SVD和BD两种预编码时分布式天线系统下行容量平衡的功率分配方案。在预编码策略方面，本项目提出了基于正交预编码的稀疏预编码方案，并获得了与穷举法近似的容量性能。