Trajectory planning for OTFS-based UAV communications

Unmanned aerial vehicles (UAVs) have attracted growing research interests in recent years, which can be used as cost-effective aerial platforms to transmit collected data packets to ground access points (APs). Thus, it is crucial to investigate robust air-tos-ground (A2G) wireless links for high-speed UAVs. However, the A2G wireless link is unstable as it suffers from large path-loss and severe Doppler effect due to the high mobility of UAVs. In order to meet these challenges, we propose an orthogonal time frequency space (OTFS)-based UAV communication system to relief the Doppler effect. Besides, considering that the energy of UAV is limited, we optimize the trajectory planning of UAV to minimize the energy consumption under the constraints of bit error rate (BER) and transmission rate, where the Doppler compensation is taken into account. Simulation results show that the performance of OTFS-based UAV system is superior to orthogonal frequency division multiplexing (OFDM)-based UAV systems, which can accomplish transmission tasks over shorter distances with lower energy consumption.