Performance Analysis of a Terrestrial/UAV Integrated Mobile Communications System Using Code Division Multiplexing in Natural Disasters

The unmanned aerial vehicle (UAV) is expected to play a role as a substitute cellular base station in mountainous regions without base stations or in natural disaster situations. To communicate with mobile phones, it is necessary to share the same frequency band between the terrestrial system and UAV system. However, the signals of both base stations cause interference with each other, and then the link quality is deteriorated. Therefore, we propose an application of code division multiplexing for UAV downlink in the terrestrial/UAvintegrated mobile communications system to improve the transmission performance. To evaluate the performance in a practical environment, we consider a cell model in which active terrestrial base stations are partially recovered in the target UAV cell area. The bit error rate performance is then numerically calculated in the cell model.