Addressing spectrum efficiency through hybrid-duplex UAV communications : challenges and opportunities

摘要: Abstract Unmanned aerial vehicles (UAVs) are set to play a prominent role in next-generation communications networks. However, the shortage of available spectrum support UAV is crucial challenge towards realizing multi-UAV To this end, hybrid-duplex (HBD) communication system, i.e., HBD-UCS, potential solution improving efficiency communications. In an UAVs with half-duplex (HD) transceivers simultaneously communicate on same full-duplex (FD) ground stations (GSs). HBD-UCSs also limited by self-interference (SI) at FD-enabled GSs and inter-UAV interference downlink UAVs. As such, accurate modeling that realistically accounts for SI necessary before any realization practical possible. regard, survey paper first discusses state-of-the-art open research problems channel modeling. Next, literature various types mitigation, FD transceiver impairments discussed. An example signal model GS considers proposed, critical technical regulatory challenges presented. At HD UAVs, management strategies can be potentially adopted discussed, together associated state-of-the-art. Furthermore, realistic performance metrics, problems, For scenarios HBD-UCSs, non-orthogonal multiple access (NOMA) techniques deployment power-domain NOMA proposed NOMA-aided HBD-UCS. Relevant then presented successive cancellation (SIC) detection, user-pairing, DL-based