Research On Wireless Ultraviolet Light Guidance Communication System In UAV Landing

Unmanned Aerial Vehicle(UAV)is widely used in various complex environments because of its convenient carrying,low cost,and good scalability.In the future,UAVs will develop in the direction of intelligence,miniaturization,and autonomize.Wireless ultraviolet(UV)communication technology can achieve communication in complex atmospheric environment,electromagnetic interference environment and radio silence environment,which can provide guarantee for communication during UAVs flight.The wireless ultraviolet MIMO communication technology provides multiple parallel transmission communication channels,which improves the information transmission rate and provides real-time and accurate data information for the UAVs during the flight.In this thesis,by applying wireless ultraviolet light communication technology to the flight guidance of UAVs,the communication stability and positioning accuracy of UAVs in complex environments are improved,and the probability of errors during the landing of UAVs is reduced,which has certain research significance.The specific research content is as follows:(1)Research on the positioning algorithm of wireless ultraviolet light guided UAV flight movement.Aiming at the flight positioning problem of UAVs in the air,a ranging model is established based on the characteristics of wireless ultraviolet light.By using MIMO communication mode to achieve the distance finding path of multiple communication links between two points,the bit error rate and distance finding error between communication links are reduced,and the distance finding accuracy is improved.Finally,the BER in the wireless ultraviolet MIMO communication link between the UAV and the ground signal transmitter during the flight is simulated and analyzed.According to the analysis,compared with the SISO communication system,the MIMO communication system with antenna array of 4×4 can improve the error code performance of the communication system by about 19dB using line-of-sight mode,while the error code performance of the communication system can be improved by about 30dB using non-line-of-sight mode.The results show that,using wireless ultraviolet light MIMO communication technology to achieve positioning during the flight of the UAVs,can greatly reduce the BER and improve the ranging accuracy.(2)The water-filling algorithm for power allocation using wireless ultraviolet light MIMO communication channel in UAVs positioning is studied.The channel matrix is decomposed into multiple independent and parallel communication channels,and different transmission powers are allocated according to the communication quality of each sub-channel.In the MIMO communication system with an antenna array of 4 ×4,when the communication distance is 50m,the channel capacity of the linear water-filling algorithm can be increased by about 7.75bit/Hz compared with that of the average power algorithm.The simulation results show that,under the condition of a certain transmission power,the use of water-filling algorithm to achieve channel power allocation can greatly increase the capacity of wireless ultraviolet MIMO communication channels,reduce the BER of MIMO communication system,and improve the stability of the MIMO communication system.In summary,this thesis mainly studies the flight positioning algorithm during the UAVs landing process,and studies the communication channel model during the UAVs landing process to ensure that the UAVs can achieve accurate and stable positioning during the flight.