Blocker-Tolerant Wideband Cognitive Spectrum Sensor

EARS（增强无线电频谱接入）计划是为了响应国会授权的2010年总统关于释放无线宽带革命的备忘录，作为国家宽带计划的一部分。它在2010年的国情咨文和后来的2012年中产阶级税收减免和创造就业法案中被引用（超过三分之一的法案涉及无线电频谱），PCAST 2012年报告[总统科学技术顾问理事会]（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）。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效率，保护被动传感服务，并使传统上服务不足的美国人能够从当前和未来的无线产品和服务中受益。这对国家经济的影响很大，正如2015年初FCC以超过450亿美元的价格竞标65 MHz频谱所看到的那样。该计划旨在提供创新、安全和弹性的频谱共享技术，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。感测、估计和检测由多个未识别（关于位置）的用户信号填充的几千兆赫的频谱带宽的问题已经引发了高度跨学科的研究奋进。这个问题是所有学科的交叉问题：信号处理，通信，系统和电路问题.最根本的挑战是估计被潜在的大信号阻断物包围的未占用频谱区域。这些未占用区域的组合带宽、线性度和动态范围要求超过现有技术的无线电接收器中的要求数倍。在过去的十年中，已经提出了认知无线电技术用于这些目的;然而，由于一些技术挑战，其发展遇到了瓶颈。该提议解决了弱机会次要用户信号与混合强/弱主要信号的更有效共存的需要，该混合强/弱主要信号目前用于商业应用、公共安全、国土安全和国防。该提案旨在设计和优化新颖和创新的认知多信道频谱传感器，实现智能和动态的下一代无线通信系统，该系统将在相同的频带上与其他宽带系统和谐共存。为了实现这一目标，提出的研究目标是：（1）干扰较弱主信号和频谱空洞的估计和检测的强主信号阻塞的粗略频率估计;（2）在射频（RF）和模拟域中的强阻塞去除系统，以过滤掉所选择的信道，从而可靠地确定机会通信;（3）基于局部最大功率（LMP）检测器的信号处理新技术，用于微弱原始信号和频谱空洞的估计和检测。

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.