EARS: Compact Adaptive MIMO Receivers

紧凑型自适应MIMO接收机布赖恩A.弗洛伊德、雅各布J.亚当斯和布赖恩L. Hughes北卡罗莱纳州立大学电气与计算机工程系学术成就：多输入多输出（MIMO）通信研究表明，在发射机和接收机处使用多个天线可以显著提高无线多径信道的容量。 由于许多无线设备在尺寸上受到限制，使用多个天线需要紧密的间隔，这导致天线之间的强的频率依赖性耦合。耦合会严重降低接收功率、分集和容量。先前的工作表明，在接收器的阻抗匹配可以收回大部分损失的系统容量;然而，这些匹配网络可能是复杂的，难以实现，它们必须适应不断变化的信道和天线条件。最后，用于MIMO系统的现有天线是以自组织方式设计的，没有考虑找到完全捕获所有可用自由度并最大化孔径容量的方法。本计画的目标是结合联合收割机资讯理论、天线工程与射频电路设计，以实现小型化宽频多天线接收机。整体的方法是开发多模天线，可重新配置的接收机，和通信算法，在一致行动，以最大限度地提高容量的基础信道。 具体而言，将开发一种系统的方法来设计MIMO天线的基础上的信息理论的指标，如容量，通过控制和成形的本征模的互耦合。 新型MIMO接收机也将开发，采用可重新配置的基带阻抗匹配网络，使用无源混频器优先架构将频率转换为RF。 最后，将开发通信和信号处理算法，以有效地检测和调整匹配网络，以响应不断变化的信道条件。 为了评估这些新技术，将构建一个硬件测试平台，包括一个双端口自适应MIMO接收机，双端口紧凑型天线，以及用于控制和信号处理的数字接口。 最后，将探讨扩展到更大的多端口系统的技术的性能和复杂性的缩放。更广泛的影响：这个多学科的项目提供了一个MIMO接收机设计的整体视图，并开发新的模型，天线设计方法，通信算法和匹配技术，可以显着提高未来的蜂窝和无线局域网的容量和性能。 如果成功，该项目将使MIMO技术即使在具有强天线互耦的物理小接收器中也能使用，从而提高数据速率、更大范围和/或更长的电池寿命。 理论与实验的结合将为学生提供各级参与的机会。

EARS: Compact Adaptive MIMO ReceiversBrian A. Floyd, Jacob J. Adams, and Brian L. HughesDepartment of Electrical and Computer EngineeringNorth Carolina State UniversityIntellectual Merit: Research on multi-input multi-output (MIMO) communications has shown that using multiple antennas at both the transmitter and receiver can dramatically improve the capacity of wireless multipath channels. Since many wireless devices are limited in size, using multiple antennas requires close spacing which leads to strong, frequency-dependent coupling between antennas. Coupling can profoundly reduce received power, diversity and capacity. Prior work suggests that impedance matching at the receiver can reclaim most of the lost system capacity; however, these matching networks can be complex and difficult to implement, and they must adapt to changing channel and antenna conditions. Finally, existing antennas for MIMO systems are designed in an ad hoc manner, with no consideration given to finding methods to fully capture all available degrees of freedom and maximize the capacity of the aperture. The goal of this project is to combine information theory, antenna engineering, and radio-frequency (RF) circuit design to enable new approaches to realize compact broadband multi-antenna receivers. The overall approach is to develop multi-mode antennas, reconfigurable receivers, and communication algorithms that act in concert to maximize capacity of the underlying channel. Specifically, a systematic method will be developed to design MIMO antennas based on information-theoretic metrics, such as capacity, by controlling and shaping mutual coupling of the eigenmodes. Novel MIMO receivers will also be developed that employ reconfigurable baseband impedance matching networks which are frequency translated to RF using passive mixer-first architectures. Finally, communication and signal processing algorithms will be developed that can efficiently sense and adjust the matching networks in response to changing channel conditions. To evaluate these new technologies, a hardware test-bed will be constructed consisting of a two-port adaptive MIMO receiver, two-port compact antenna, and a digital interface for control and signal processing. Ultimately, the scaling of performance and complexity will be explored as the techniques are extended to larger multi-port systems.Broader Impacts: This multi-disciplinary project provides a holistic view of MIMO receiver design and develops new models, antenna design methods, communications algorithms and matching techniques which could significantly increase the capacity and performance of future cellular and wireless local area networks. If successful, this project would enable MIMO techniques to be employed even in physically small receivers with strong antenna mutual coupling, allowing increased data rates, larger range, and/or longer battery lives. The combination of theory and experiment will provide opportunities for student participation at all levels.