Detection of Incumbent Radar in the 3.5 GHZ CBRS Band

Abstract

In the 3.5 GHz Citizens Broadband Radio Service (CBRS), 100 MHz of spectrum will be shared between commercial users and federal incumbents. Dynamic use of the band relies on a network of sensors dedicated to detecting the presence of federal incumbent signals and triggering protection mechanisms when necessary. This paper uses field-measured waveforms of incumbent signals in and adjacent to the band to evaluate the performance of matched-filter detectors for these sensors. We find that the proposed detectors exceed the requirements for performance in the presence of co-channel interference from commercial long term evolution (LTE) signals, meaning that more commercial devices can use the band in the proximity of sensors. Furthermore, the detectors are robust to out-of-band emissions into this band from adjacent-band radars, which prior studies have found can be significant.