Impact of CFO on Low Latency-Enabled UAV Using "Better Than Nyquist" Pulse Shaping in GFDM

Low altitude aerial base stations onboard unmanned aerial vehicles (UAVs) have recently gained a lot of attention to provide cellular coverage to mobile ground users. In this paper we evaluate the effect of carrier frequency offset (CFO) on the symbol error rate in the downlink of such systems, where a long-term evolution (LTE) compatible time-frequency grid based on generalized frequency division multiplexing (GFDM) is considered. The choice of GFDM as multi-carrier modulation scheme is motivated by its widely proposed application in fifth generation cellular systems and its backward compatibility with LTE. Simulation results are shown for "Better than the Nyquist (BTN)" pulse shaping filters in three different environments: Suburban, Urban and Urban High Rise. The use of BTN pulse shaping filters allows for higher robustness to CFO as compared to base line pulse shaping filer know as root-raised cosine filters for different environments conditions. Simulation results are presented considering realistic air-to-ground propagation conditions generated from the commercial Wireless InSite ray-tracing radio propagation software.