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Institute for Telecommunication Sciences
the research laboratory of the National Telecommunications and Information Administration

Frank H. Sanders; John E. Carroll; Geoffrey Sanders; Robert L. Sole; Robert J. Achatz; Lawrence S. Cohen

Abstract: In response to proposals to introduce new Long Term Evolution (LTE) microcell Citizens Broadband Service (CBS) radio systems into 3550–3650 MHz (3.5 GHz) radio spectrum in the United States, the authors have performed measurements and analysis on effects of LTE interference on the performance of a type of radar receiver that might eventually share spectrum with such systems. LTE and Gaussian noise interference were injected into a radar receiver; Gaussian noise was a proxy for aggregated interference sources and one type of LTE. Interference was injected into a radar receiver so as to appear coincident with synthetic radar targets on the radar’s display. The targets’ baseline (non-interference) probability of detection (Pd) was 90 percent. With interference present, the targets’ Pd was measured and recorded as a function of LTE signal (both on-tuned and off-tuned) and Gaussian noise interference levels. Additional data presented in this report include: the radar receiver’s antenna radiation pattern, RF front end frequency response, IF-stage frequency response, noise figure, and RF overload response up to an input power of -4.6 dBm. A measured LTE emission spectrum is also provided. Using these data, spectrum management personnel can perform electromagnetic compatibility (EMC) analyses for possible future spectrum sharing between LTE transmitters and this type of radar receiver.

Keywords: radar; spectrum sharing; Long Term Evolution (LTE); Citizens Broadband Service (CBS); interference effects; interference protection criteria (IPC); microcells; small cells; spectrum access system (SAS); 3.5 GHz band

To request a reprint of this report, contact:

Lilli Segre, Publications Officer
Institute for Telecommunication Sciences
(303) 497-3572

For technical information concerning this report, contact:

Frank H. Sanders
Institute for Telecommunication Sciences
(303) 497-7600

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

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