Collaborative Research: CCSS: Towards Energy-Efficient Millimeter Wave Wireless Networks: A Unified Systems and Circuits Framework

无线通信对经济、教育、医疗、娱乐、物流和旅游等多个领域产生了重大影响。为了满足日益增长的对更高数据速率和带宽的需求，第五代(5G)无线网络设想在包括6 GHz以上频率的频谱中进行通信，特别是毫米波(mm波)频段。与工作在较低频段的当前RF(射频)系统相比，在毫米波系统中应用高载波频率允许更大的信道带宽。然而，构成电路和系统组件(如模数转换器(ADC)和数模转换器(DAC))的能耗随着带宽的增加而显著增加。在毫米波多输入多输出(MIMO)系统中，大量的收发天线数量和较大的带宽导致了大量的ADC/DAC能量消耗，这与移动设备和小小区接入点有限的能量预算不一致。这表明迫切需要毫米波收发机设计的节能解决方案。该项目通过提出新颖的收发信机架构、电路模块和设计技术以及相关的通信策略来应对这些挑战。该项目将把研究与一个重要的教育和推广计划紧密结合起来，该计划由两个重点领域组成：(I)学生培训，和(Ii)以新课程开发和学生参与的形式传播研究成果。该项目研究了利用非线性模拟运算器和延迟元件来减少毫米波通信系统中粗略的量化速率损失，并开发了一个跨学科的框架，通过三个相互关联的推进来研究节能毫米波通信的理论和实践。第一个推力发展了必要的理论技术来研究通信的基本限制，例如在具有低分辨率ADC/DAC和收发机处的非线性模拟处理的MIMO系统中的可实现速率。第二个重点是高能效电路的设计和推力1的非线性模拟元件和延迟元件的片上实现。特别是利用晶体管非线性的Volterra-Weiner级数表示来设计非线性模拟运算器并分析其性能。第三个推力调和了推力2中开发的电路的实际限制，与推力1中的理论推导中所做的假设相一致，并提出了用于毫米波通信的实用的、可实现的通信协议。这包括为所提出的通信系统设计信道估计、多用户调度和ADC分配机制。拟议的研究工作导致了一个统一的框架，以研究毫米波收发机的电路设计和实现，以及与收发机电路设计相匹配的多用户波束形成、调度和数据传输机制。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Wireless communications has had a major impact on a diverse range of areas such as economy, education, health, entertainment, logistics, and travel. In order to satisfy the ever-growing demand for higher data-rates and bandwidth, the fifth generation (5G) of wireless networks envisions communication in a spectrum which includes frequencies above 6 GHz and especially the millimeter wave (mm-wave) bands. The application of high carrier frequencies in mm-wave systems allows for larger channel bandwidths compared to the current RF (radio frequency) systems which operate in lower frequency bands. However, the energy consumption of constituent circuit and system components such as analog to digital converters (ADCs) and digital to analog converters (DACs) increases significantly with bandwidth. The massive number of transceiver antennas and large bandwidth lead to substantial ADC/DAC energy consumption in mm-wave multiple-input multiple-output (MIMO) systems which is inconsistent with the limited energy budget in mobile devices and small-cell access points. This points to an urgent need for energy-aware solutions to mm-wave transceiver design. The project addresses these challenges by proposing novel transceiver architectures, circuit blocks and design techniques, and associated communication strategies. The project will tightly integrate research with a significant education and outreach program consisting of two focus areas: (i) Student training, and (ii) Disseminating research outcomes in the forms of new curricular development and student involvement. A concerted effort will be made to broaden the participation of women and students from under-represented communities in the project.The project investigates the use of nonlinear analog operators and delay elements to mitigate the coarse quantization rate-loss in mm-wave communication systems, and develops an interdisciplinary framework for investigating the theory and practice of energy-efficient mm-wave communication through three interrelated thrusts. The first thrust develops the theoretical techniques necessary to study the fundamental limits of communication, such as achievable rates, in MIMO systems with low resolution ADC/DACs and nonlinear analog processing at the transceivers. The second thrust focuses on energy-efficient circuit design and on-chip implementation of nonlinear analog components and delay elements of Thrust 1. In particular, the Volterra-Weiner series representation of transistor nonlinearity is used to design nonlinear analog operators and analyze their performance. The third thrust reconciles the practical limitations of circuitry developed in Thrust 2, with the assumptions made in the theoretical derivations in Thrust 1, and proposes practical, implementable communication protocols for mm-wave communications. This includes the design of channel estimation, multiuser scheduling, and ADC allocation mechanisms for the proposed communication systems. The proposed research effort leads to a unified framework to study the circuit design and implementation of mm-wave transceivers, along with multiuser beamforming, scheduling, and data transmission mechanisms matched with the transceiver circuit design.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.