PSUN: An OFDM-Pulsed Radar Coexistence Technique with Application to 3.5 GHz LTE

This paper proposes Precoded SUbcarrier Nulling (PSUN), an orthogonal frequency-division multiplexing (OFDM) transmission strategy for a wireless communications system that needs to coexist with federal military radars generating pulsed signals in the 3.5 GHz band. This paper considers existence of Environmental Sensing Capability (ESC), a sensing functionality of the 3.5 GHz band coexistence architecture, which is one of the latest suggestions among stakeholders discussing the 3.5 GHz band. Hence, this paper considers impacts of imperfect sensing for a precise analysis. Imperfect sensing occurs due to either a sensing error by an ESC or a parameter change by a radar. This paper provides a framework that analyzes performance of an OFDM system applying PSUN with imperfect sensing. Our results show that PSUN is still effective in suppressing ICI caused by radar interference even with imperfect pulse prediction. As an example application, PSUN enables LTE downlink to support various use cases of 5G in the 3.5 GHz band.