Collaborative Research: Radio Frequency Interference Aware Radio Astronomy Systems

The University Of Texas Rio Grande Valley, Edinburg TX

Investigators

Abstract

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 staggering growth of wireless communications systems has led to an increasing demand for spectrum to support commercial services, particularly in the frequencies below 3 GHz, where battery-powered mobile devices such as smart phones and tablets operate most efficiently. It is desirable for such devices to be useful for a variety of applications, and in a variety of locations that have differing available spectrum. Currently this is achieved, in a smart phone for example, by a collection of hardware solutions, with one for each standard. This is complex and expensive, and such receivers will not be sufficiently adaptable for future spectrum usage. It is desirable to have a single hardware solution that is capable of receiving a broad spectrum and then selecting a particular transmission from it a based on the local spectral conditions and the application. Adaptable solutions such as this do not currently exist due in large part to the interference that occurs when a desired signal is weak and is crowded by a channel containing a high power signal. There are high dynamic range receivers that tolerate such disparate signal levels, but they are not adaptable over large bandwidths. In this project, a novel high-dynamic range receiver topology that promises to enable the reception of a wide instantaneous bandwidth will be explored. The topology is enabled by new signal processing concepts and integrated circuit technologies. The research undertaken will range from the basic theory to experimental demonstration. Reducing the impact of radio frequency interference (RFI), e.g., cellular, radio, TV, satellite and radar signals, and interference from microwave ovens, is crucial for the future of radio astronomical discoveries. When studying celestial radio signals, it is not uncommon for the scientists to puzzle over mysterious interference. To avoid RFI, the radio astronomers select sparsely populated areas to set up their telescopes. In some cases, the quiet zones around the radio telescopes have to be established to limit the use of airwares. Therefore, the technology of RFI mitigation is a critical component needed by radio astronomy science in increasingly challenging RFI environments. This project brings together researchers in radio astronomy, statistical array signal processing, radio frequency instrumentation, digital signal processing, wireless communications, and software defined radios to address these challenges and boost the science of radio astronomy by introducing a novel framework that provides the necessary analytical tools for modeling, analyzing, and operating radio telescope arrays in complex RFI environments. Mitigating RFI in radio astronomy is an interdisciplinary research area which combines the efforts of scientists from various fields including electrical engineering, physics, astronomy, computer science, and astrophysics. Opportunities created by developing RFI mitigation techniques by the joint team of University of Texas at Dallas (UTD) and the Center for Advanced Radio Astronomy (CARA) of the University of Texas at Rio Grande Valley (UTRGV) researchers will have a direct impact in the number of students participating in STEM careers. The success of this project will be beneficial to both the commercial and the scientific communities. Recently, CARA teamed up with SpaceX, a leading commercial manufacturer of orbital launch vehicles, to create the Space Craft Tracking and Astronomical Research into Gigahertz Astrophysical Transient Emission (STARGATE), a space technology innovation center that combines higher education, research, economic development, and commercialization. The future connections developed between STARGATE's technology/business incubator and the Dallas Telecom Corridor will open up new opportunities for technology transfer and better planning of spectrum use.