SWIFT: Advancing Coexistence through a Cross-Layer Design Platform with an Adaptive Frequency-Selective Radio Front-End and Digital Algorithms

随着频谱的不断拥挤，创造新的设备、电路和计算算法变得越来越重要，这些设备、电路和计算算法能够在无线信号的接收和处理期间自适应地抑制不必要的电磁干扰。该项目的核心是实现一个开发平台，使无线通信收发器能够跨越不同的学科界限进行设计。该设计平台将允许新设备和电路的原型设计，以及新的可重构计算和无线通信算法。该研究旨在为增强型射频（RF）通信系统奠定基础，该系统利用实时调谐来适应不同的频谱环境，以实现更高的干扰容限，并提供设计技术和工具，以改善无线设备在各种场景中的共存。通过使更紧凑的设备具有更高的性能，抗干扰能力和可靠性的数字控制调谐，这项研究将有助于改善我们社会的福祉，越来越多地依赖于无线设备和系统来满足过多的需求。该项目还将为研究生和本科生的培训奠定基础，他们可以应用和开发涉及设备，电路和计算算法的跨层设计技术。 这项研究将为下一代RF接收机的协同设计提供一个平台和第一个硬件原型，该接收机能够抑制通道内和相邻通道干扰，而不会影响可能具有比干扰低得多的功率的期望信号的接收。时间调制器件设计的最新进展已经导致形成频率选择性限制器（FSL）的可能性，该频率选择性限制器（FSL）可以本质上区分和衰减以高于某个阈值的功率电平为特征的干扰。然而，为了实现可以保护各种现有无线电的接收器模块的FSL，这些部件需要具有高品质因数（Q 2，000）的新的单片集成谐振器以及具有低损耗角正切、宽调谐范围和低电容值的变容二极管。通过利用氮化铝钪（AlScN）薄膜的声学特性和铪锆氧化物（HZO）原子层的铁电特性，该研究通过开发完全集成的微机电系统（MEMS）FSL解决了这一根本挑战，该FSL可以与互补金属氧化物半导体（CMOS）工艺兼容性制造，并且当在拥挤的频谱环境中操作时，可以通过模拟CMOS电路有意地调谐以实现最佳可能的数字信号处理结果。AlScN/HZO组件将与定制设计的模拟电路共同开发，以实现基于检测到的功率水平的自适应特性，从而在设备和系统级别上持续优化信号处理质量。为了扩大无线系统各层的优势，数字共存算法和自适应模拟前端电路将被设想为战略性地调整FSL和接收器电路的工作点，以实现最高的通信质量。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响力审查标准进行评估，被认为值得支持。

As the crowding of the frequency spectrum continues, it becomes increasingly important to create new devices, circuits and computational algorithms with the ability to adaptively suppress unwanted electromagnetic interference during the reception and processing of wireless signals. This project is centered around the realization of a development platform that can enable transceivers for wireless communication to be designed across different disciplinary boundaries. The design platform will allow the prototyping of new devices and circuits, together with new reconfigurable computing and wireless communication algorithms. The research aims to lay the groundwork for enhanced radio frequency (RF) communication systems that make use of real-time tuning to adapt to different spectrum environments for higher interference tolerance, as well as to provide design techniques and tools that improve the coexistence of wireless devices in a broad range of scenarios. By enabling more compact devices with higher performance, interference robustness and digitally-controlled tuning for reliability, this research will help improve the well-being of our society that increasingly relies on wireless devices and systems for a plethora of needs. The project will also establish a foundation for the training of graduate and undergraduate students who can apply and develop cross-layer design techniques involving devices, circuits and computational algorithms. This research will provide a platform and first hardware prototypes for the co-design of next-generation RF receivers with the ability to suppress both in-channel and adjacent channel interferers without compromising the reception of desired signals that may have much lower power than the interferers. Recent progress in the design of time-modulated devices has led to the possibility to form frequency selective limiters (FSLs), which can intrinsically distinguish and attenuate interference characterized by power levels higher than a certain threshold. However, to realize FSLs that can protect receiver modules of various existing radios, these components require new monolithically integrated resonators with high quality factors (Q 2,000) and with varactors having low loss-tangents, wide tuning ranges and low capacitance values. By taking advantage of the acoustic properties of Aluminum Scandium Nitride (AlScN) thin-films and of the ferroelectric properties of Hafnium Zirconium Oxide (HZO) atomic layers, the research addresses this fundamental challenge through the development of fully integrated microelectromechanical system (MEMS) FSLs that can be manufactured with complementary metal-oxide-semiconductor (CMOS) process compatibility, and that can be deliberately tuned by analog CMOS circuits towards accomplishing the best possible digital signal processing results when operating in crowded spectral environments. The AlScN/HZO components will be co-developed with custom-designed analog circuits to achieve adaptive characteristics based on detected power levels, allowing to continuously optimize the signal processing quality at both device and system levels. To broaden the benefits across wireless system layers, digital coexistence algorithms and adaptive analog front-end circuits will be conceived to strategically tune the operating points of the FSLs and of the receiver circuits towards the highest communication quality. A prototyping platform with a reconfigurable field-programmable gate array (FPGA) will be constructed to develop the digital coexistence algorithms and apply them to Bluetooth Low Energy, Zigbee and Wi-Fi signals.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.