Massive MIMO Systems for Communication and Localization

多天线技术是当前和未来无线通信和定位系统的关键要素。传统上，天线的数量针对多输入多输出（MIMO）通信和定位系统设想的无线电收发器（每个无线电收发器包括独立的收发器）已经被限制到相对小的数量，比如说20个或更少。已经表明，如果基站处的天线数量增加到数百甚至数千，天线，从而产生所谓的大规模或大规模MIMO系统。虽然在过去的两年中，大量的理论研究已经致力于大规模MIMO通信系统，信号处理和信号设计的显着改进仍然是必要的，大规模MIMO通信系统可以在实践中部署之前。此外，虽然预计在大规模MIMO通信系统中观察到的增益会转移到定位问题，但尚未研究该问题。此外，大量的天线和相干收发器以及大的预期数据速率需要新的电路和系统设计方法来实现大规模MIMO系统，因为小规模MIMO系统架构不能简单地按比例放大到大规模MIMO系统。此外，常用的MIMO系统和信道模型的有效性提出了质疑。因此，要达到有意义的结果，在现实环境中的信道测量是必要的，现有的模型的硬件损伤进行验证，并可能适当修改。这些考虑强调了灵活的MIMO测试平台的必要性，用于优化和验证理论结果。 因此，在这个项目中，我们将采取整体方法来进行大规模MIMO系统设计，将我们在信号处理和通信（数字通信研究所，IDC，斯科贝尔），定位和天线设计（微波和光子学研究所，LHFT，Vossiek）以及收发器设计和实施（技术电子研究所，LTE，Weigel）方面的集体专业知识结合起来。该项目有以下四个具体目标：1）开发计算效率高，安全，鲁棒，高性能的预编码和检测策略。2）设计具有非常稳定的相位特性的天线。3）开发新的同步协议，多径分离算法和定位技术。4)开发能够实现大规模MIMO系统的电路和系统架构。目标1）-4）将通过理论研究和在大规模MIMO测试平台上实现/验证所开发的算法、电路和系统架构来实现。

Multiple-antenna technology is a key element of current and future wireless communication and localization systems. Traditionally, the number of antennas (each including an independent transceiver) envisioned for multiple-input multiple-output (MIMO) communication and localization systems has been limited to a comparatively small number, say 20 or less. However, recently, it has been shown that multiuser MIMO communication systems exhibit several favorable properties if the number of antennas at the base station is increased to hundreds or even thousands of antennas, giving rise to so-called large-scale or massive MIMO systems. Although a large amount of theoretical research has been dedicated to massive MIMO communication systems in the past two years, significant improvements in signal processing and signal design are still necessary before massive MIMO communication systems can be deployed in practice. Furthermore, while it is expected that the gains observed in massive MIMO communication systems carry over to localization problems, this issue has not been investigated yet. Moreover, the large number of antennas and coherent transceivers, and the large expected data rates require new approaches to circuit and system design for implementation of massive MIMO systems, since small-scale MIMO system architecures cannot simply be scaled up to massive MIMO systems. Furthermore, the validity of the commonly used MIMO system and channel models are put in question. Therefore, to arrive at meaningful results, channel measurements in realistic environments are necessary and existing models for hardware impairments have to be verified and possibly suitably modified. These considerations underline the necessity of a flexible MIMO testbed for optimization and verification of theoretical results. Thus, in this project, we will take a holistic approach to massive MIMO system design bringing together our collective expertise in signal processing and communication (Institute for Digital Communications, IDC, Schober), localization and antenna design (Institute for Microwaves and Photonics, LHFT, Vossiek), and transceiver design and implementation (Institute for Technical Electronics, LTE, Weigel). The proposed project has the following four specific objectives: 1) Development of computationally efficient, secure, robust, and high performance precoding and detection strategies.2) Design of antennas with very stable phase characteristic.3) Development of novel synchronization protocols, multipath separation algorithms, and localization techniques. 4) Development of circuit and system architectures enabling the implementation of massive MIMO systems.Objectives 1)-4) will be achieved through both theoretical research and implementation/verification of the developed algorithms, circuits, and system architectures in a massive MIMO testbed.