CIF: Small: RUI: Multiple-Antenna Systems in Spatially Distributed Networks with Non-Idealized Assumptions

随着无线通信设备的普及，电磁频谱变得越来越稀缺。目前的研究表明，通过在每个无线设备上使用多个天线，可以显著提高用户密度，共享电磁频谱，而不会降低单个用户的性能。然而，该领域的大多数现有研究都是基于理想化的系统模型，这些模型往往是不现实的。该项目研究了使用理想化网络模型预测的多天线系统的有希望的性能增益在多大程度上适用于具有更现实假设的网络模型，并且是现有理论理解和未来实际实施之间的重要桥梁，该技术可能会显著缓解频谱拥挤问题。现有的多天线节点空间分布无线网络研究大多基于用户均匀随机空间分布、天线间信道不相关、信道状态信息（CSI）准确可用等理想模型；在实践中常常站不住脚的假设。研究者正在研究非均匀节点分布、信道相关性和不准确的CSI对多天线节点无线网络性能的影响。解决的具体问题包括：1)在这样的网络中可以实现什么样的频谱效率？2)在这样的网络中，随着用户密度的增加，每个用户的天线数量可以在多大程度上保持恒定的链路数据速率？3)空间分布网络的空间节点分布、通道相关性和CSI不确定性的合适模型是什么？这些问题的答案有助于提高对实际系统中多天线系统性能优势的现有理解，特别是它们在实践中缓解频谱拥挤的潜力。

The electromagnetic spectrum is becoming scarce as the usage of wireless communications devices becomes ubiquitous. Current research has shown that by using multiple antennas at each wireless device, significantly higher densities of users can share the electromagnetic spectrum without reducing the performance of individual users. Most existing research in this area however is based on idealized system models that are often unrealistic. This project studies the extent to which the promising performance gains of multi-antenna systems predicted using idealized network models apply to networks models with more realistic assumptions, and is an important bridge between existing theoretical understanding and future practical implementation of a technology that could potentially alleviate the spectral crowding problem significantly.Most existing research on spatially-distributed wireless networks with multi-antenna nodes is based on idealized models such as uniformly random spatial distribution of users, uncorrelated channels between antennas, and the availability of accurate channel-state-information (CSI); assumptions which often do not hold in practice. The investigator is studying the impact of non-uniform node distributions, channel correlations, and inaccurate CSI on the performance of wireless networks with multi-antenna nodes. Specific questions addressed include 1) What spectral efficiencies can be achieved in such networks? 2) To what extent can increasing the number of antennas per user with user density maintain constant perlink data rates in such networks? 3) What are appropriate models for spatial node distribution, channel correlation, and CSI uncertainty for spatially distributed networks? Answers to these questions help improve existing understanding of the performance benefits of multiple-antenna systems in realistic systems and in particular, their potential to alleviate spectral crowding in practice.