Blocker-Tolerant Wideband Cognitive Spectrum Sensor

这个EAR(增强无线频谱接入)计划是为了响应2010年总统关于释放无线宽带革命的备忘录而建立的，该备忘录是国会授权的，是国家宽带计划的一部分。它在2010年的国情咨文和后来的2012年《中产阶级减税和创造就业法案》(该法案的三分之一以上涉及无线电频谱)、2012年PCAST报告[总统科学和技术顾问委员会](该报告呼吁大幅增加频谱共享的使用)和2013年总统备忘录(扩大美国在无线创新方面的领导地位)中被提及。该计划的目的是确定大胆的新概念，这些概念有可能有助于显著提高无线电频谱利用的效率，保护被动侦听服务，并提高传统上服务不足的美国人从当前和未来的无线产品和服务中受益的能力。这对国家的经济影响很大，正如2015年初FCC上一次以超过450亿美元的价格竞标65 MHz频谱所看到的那样。它将使科学、工程、工业、民用和军事用户能够使用射频频谱。这项建议的目标是提供一种创新、安全和弹性强的频谱共享技术，以改善消费电子行业的无线宽带通信，并提高关键政府服务的频谱可用性。感知、估计和检测几吉赫兹的频谱带宽的问题已经引发了一项高度跨学科的研究工作。这个问题是所有这些学科的交叉问题：信号处理、通信、系统和电路问题.根本的挑战是估计被潜在的大信号阻滞器包围的空闲频谱区域。这些空闲区域的综合带宽、线性度和动态范围要求比最先进的无线电接收器高出数倍。在过去的十年里，认知无线电技术被提出用于这种目的；然而，由于几个技术挑战，它的发展遇到了瓶颈。该建议解决了弱机会性二次用户信号与当前用于商业应用、公共安全、国土安全和国防的混合强/弱一次信号更有效地共存的需求。这项建议旨在设计和优化新颖和创新的认知多通道频谱传感器，使智能和动态的下一代无线通信系统能够与其他宽带系统在相同频段和谐共存。为实现这一目标，拟议的研究目标是：(1)干扰较弱的一次信号和频谱空洞的估计和检测的强一次信号阻塞器的粗略频率估计；(2)射频(RF)和模拟域的强阻塞器去除系统，以滤除选定的信道以可靠地确定机会通信；(3)基于局部最强(LMP)检测器的新的信号处理技术，用于估计和检测弱一次信号和频谱空洞。

This EARS (Enhancing Access to the Radio Spectrum) program was founded in response to the 2010 Presidential Memorandum on Unleashing the Wireless Broadband Revolution mandated by Congress as part of the National Broadband Plan. It was referenced in 2010 State of the Union and later on the Middle Class Tax Relief and Job Creation Act of 2012 (More than 1/3 of the bill deals with radio spectrum), the PCAST 2012 Report [President's Council of Advisors on Science and Technology] (which calls for vastly increased use of spectrum sharing) and the 2013 Presidential memo (Expanding America's Leadership in Wireless Innovation). The aim of this program is to identify bold new concepts with the potential to contribute to significant improvements in the efficiency of radio spectrum utilization, protection of passive sensing services, and in the ability for traditionally underserved Americans to benefit from current and future wireless-enabled goods and services. The impact is large on the economics of the Nation as seen on the last FCC bidding of 65MHz of the spectrum for over $45 billion early in 2015. It will enable access to science, engineering, industry, civilian and military users of the radio frequency (RF) spectrum.The objective of this proposal is to provide an innovative, secure and resilient spectrum-sharing technology to improve wireless broadband communications for the consumer electronics sector and enhance spectrum availability for critical government services. The problem of sensing, estimating and detecting several gigahertz of a spectrum bandwidth populated by a number of unidentified (as to location) user's signals has unleashed a highly interdisciplinary research endeavor. This problem a crosscutting problem in all these disciplines: signal processing, communications, systems, and circuit problem. The fundamental challenge is to estimate unoccupied spectrum regions that are surrounded by potentially large signal blockers. The combined bandwidth, linearity and dynamic range requirements of these unoccupied regions exceed that found in state-of-art of radio receivers by several times. Cognitive radio technology has been proposed for such purposes over the last decade; however, its development has run into bottlenecks due to several technological challenges. This proposal addresses the need for a more efficient coexistence of weak opportunistic secondary user signals with mixed strong/weak primary signals that are currently used for commercial applications, public safety, homeland security, and national defense. This proposal aims at designing and optimizing novel and innovative cognitive multi-channel spectrum sensors, enabling smart and dynamic next-generation wireless communication systems, which will coexist harmonically with other broadband systems over the same frequency bands. To accomplish this goal, the proposed research objectives are: (1) coarse frequency estimation of strong primary signal blockers that interfere with the estimation and detection of weaker primary signals and spectrum holes; (2) strong blocker removal system in the radio frequency (RF) and analog domain to filter out the selected channel for reliable determination of opportunistic communications; (3) novel signal processing techniques based on locally most powerful (LMP) detectors for the estimation and detection of weak primary signals and spectrum holes.