Collaborative Research: MIMO Networking: From Principles to Protocols

近年来，出现了用于通信网络的复杂的多输入多输出(MIMO)技术。要实现此类技术承诺的显著性能提升，不仅需要开发合适的网络协议，还需要基于对超越层次结构中各个层的问题的仔细考虑，重新考虑相关网络体系结构的各个方面。到目前为止，大多数工作都集中在物理层和介质接入层，强调编码和多路复用问题。然而，人们逐渐认识到，更高网络层的问题至少同样重要和同样丰富，而且相关的对MIMO网络设计挑战的更广泛看法对于实现这项技术的性能潜力至关重要。拟议的研究正是针对这些挑战，并将从基本原则开始，开发有效和强大的网络协议和资源管理算法所遵循的关键见解。随着人们对802.16和802.11n等标准的发展产生了浓厚的兴趣，这种研究特别及时，产生实际影响的潜力特别高。这一更广泛的研究主题将通过调查几个具体问题和问题来探讨。最重要的是调度问题：假设一条MIMO链路用于将数据传输到一组最终用户，在这种系统中可以实现的吞吐量、延迟、可靠性、公平性和复杂性之间的基本权衡是什么？在我们的初步研究中，我们已经确定了从根本上说新的时空调度协议可以而且必须被开发，并且这些协议的结构与它们的非MIMO对应的那些显著不同。在拟议的研究中，我们将研究如何在任何给定的传输间隔内选择用户，如何利用反馈，以及如何完成训练。研究将进一步探讨当这种类型的多个MIMO链路相互结合使用时的更丰富的问题，就像任何实际网络中的情况一样。在这样的环境下，协作和转发成为高效调度和资源管理不可或缺的方面，研究将继续深入研究此类算法的发展。在整个研究过程中，我们将考虑强大的网络动态，包括多径衰落和阴影、用户连通性和人口的快速波动，以及此类网络中流量的突发性。我们的研究的显著特征包括：1)比迄今认为的更强的最优性概念；2)除了简单的渐近性之外的更精细的粒度分析；3)在协议设计和分析中，将传统的信息论和通信论处理与排队理论、调度理论和算法理论的处理紧密结合。事实上，更广泛地说，要调查的问题范围将需要协调应用广泛的设计和分析工具，使研究具有高度跨学科的性质。事实上，这些工具将来自信息论、排队论、通信论、图论、编码论、算法和复杂性理论、估计理论和机器学习。智力价值：拟议的研究将显著推进利用MIMO技术的系统联网的基本理论和实践，并为开发支持新一代应用所需的更高性能的联网基础设施提供坚实的基础。广泛影响：拟议的研究是一项高度以教育为中心的活动，重点是学生的专业和智力发展。通过外展努力，PI将继续坚定地致力于让传统上在工程学方面代表性较低的群体的学生参与他们的研究项目。国际和平研究所还坚定地致力于将这项研究的结果纳入课程，特别是将网络和物理层的设计和分析具体结合起来的各自机构正在开发的新网络科目。最后，研究计划将有助于促进两个学术机构之间重要的新的实验室间研究合作，这两个机构有可能建立强有力的伙伴关系，以及与其他关键的行业合作伙伴。特别是，拟议的努力将促进俄亥俄州立大学和麻省理工学院在通信和网络领域的更紧密的研究和教育联系，并通过与惠普、诺基亚和通用电气的网络实验室的密切互动，迅速将由此产生的研究成果转化为实践，这些实验室都对有效的学术-产业研究合作有着坚定的承诺和记录。PI将大力利用这些关系以及早期的基础设施投资，例如惠普在麻省理工学院过去几年建立的无线网络跨学科中心，以促进麻省理工学院内外的这种合作。

Recent years have seen the advent of sophisticated multiple-input, multiple-output (MIMO) technology for communication networks. Achieving the substantial performance gains promised by such technology requires not only the development of suitable network protocols, but also rethinking aspects of the associated network architecture based on careful consideration of issues that transcend individual layers in the hierarchy. To date, most effort has focused on the physical and medium-access layers, emphasizing coding and multiplexing issues. However, there is an emerging appreciation that the issues at the higher networking layers are at least as important and equally rich, and that the associated broader view of MIMO network design challenge is critical to realizing the performance potential of this technology. The proposed research is aimed at precisely these challenges, and will start from fundamental principles to the develop key insights from which efficient and robust networking protocols and resource management algorithms will follow. With the strong interest in the development of standards such as 802.16 and 802.11n, among many others, such research is especially timely and the potential for practical impact is particularly high.This broader research theme will be approached by investigating several specific questions and issues. Of central importance is the scheduling problem: given a MIMO link for delivering data to a collection of endusers, what are the fundamental tradeoffs between throughput, delay, reliability, fairness, and complexity achievable in such systems? In our preliminary research, we have established that fundamentally new spatiotemporal scheduling protocols can and must be developed, and that the structure of such protocols is strikingly different from those in their non-MIMO counterparts. In the proposed research, we will investigate issues ranging from how users should be selected in any given transmission interval, to how feedback should be exploited, to how training should be accomplished.The research will further pursue the still richer problems when multiple MIMO links of this type areused in conjunction with one another, as is the case in any practical network. In such settings, cooperation and relaying become integral aspects of efficient scheduling and resource management, and the research will pursue the development of such algorithms in detail. Throughout our investigation, we will take into account the strong network dynamics, including multipath fading and shadowing, rapid fluctuations in user connectivity and populations, and the bursty nature of traffic in such networks.Distinguishing features of our research include its emphasis on 1) stronger notions of optimality than have been considered to date; 2) its finer grain analysis beyond simple asymptotics; and 3) its tight integration of traditional information-theoretic and communication-theoretic treatments with queuing-theoretic, scheduling-theoretic and algorithm-theoretic treatments in the protocol design and analysis. Indeed, more generally the spectrum of issues to be investigated will require the coordinated application of a wide range of design and analysis tools, making the research highly interdisciplinary in nature. Indeed, these tools will be drawn from information theory, queuing theory, communication theory, graph theory, coding theory, algorithms and complexity theory, and estimation theory and machine learning.Intellectual Merit: The proposed research will significantly advance the fundamental theory and practice of networking in systems exploiting MIMO technology, and to provide a solid foundation for the development of the higher performance networking infrastructure needed to enable a new generation of applications.Broader Impacts: The proposed research is a highly education-centered activity with a focus around the professional and intellectual development of students. Through outreach efforts, the PI's will continue their strong commitment to involving in their research programs students from groups traditionally underrepresented in engineering. The PI's are also strongly committed to the integration of the results of this research into the curriculum, and in particular to new networking subjects under development at their respective institutions that specifically integrate network- and physical-layer design and analysis. Finally, the researchprogram will help foster important new interlaboratory research collaboration between two academic institutions for which there is the potential for strong partnership, as well as with additional key industrial partners. In particular, the proposed effort will foster closer research and educational ties between OSU and MIT in the communication and networking area, and rapid transition of the resulting research results to practice through close interaction with the networking laboratories of Hewlett-Packard, Nokia, and General Electric, each of whom has a strong commitment to and track record of effective academic-industrial research collaboration. The PI's will strongly leverage these relationships, as well as earlier infrastructure investments, such as the interdisciplinary Center for Wireless Networking established by HP at MIT over the last several years to foster such collaboration both within and beyond MIT.