Research And Implementation Of UAV MIMO Channel Modeling

With the continuous development of communication technology and flight control technology, all kinds of UAVs(unmanned aerial vehicle) have been used in every aspect of production and life. Therefore, the research on communication system and flight control of UAV has become more and more popular. And in the Medium-high altitude,Medium-high speed and long time working UAV, which is the future direction of UAV development, it is indispensable to research its communication links. Due to UAV's own speed and the impact of the operating environment, communication quality is usually not guaranteed when working. So it can be an effective way to study the UAV communication channel of the fading characteristics and help formulate anti-jamming and anti-fighter plans for UAV channel in a targeted way by using reasonable mathematical models to simulate the UAV communication channel. Meanwhile, MIMO technology has made a great breakthrough in increasing the channel capacity in the wireless communication system, so in order to meet the increasing demand for communication capacity in UAV communication, it is necessary to introduce MIMO technology to the UAV communication system.Based on the characteristics of wireless channel, this paper analyzes the fading characteristics of UAV in different operation stages,and gives reasonable channel modeling at each branch stage. On this basis, combined with the characteristics of UAV channel under the MIMO, this paper models the corresponding UAV channel, and the channel model has been implemented on the FPGA hardware platform.The second chapter first analyzes the characteristics of the wireless channel fading,and then analyzes the channel characteristics of the UAV at different stages of the operation, and studies the Doppler frequency spectrum and the delay power spectrum of the channel by assuming the distribution of the scatterer. In the third chapter, three kinds of SISO flat Rayleigh channel modeling schemes are analyzed firstly, due to the fact that the channel between each pair of antennas in the MIMO system is a broadband SISO channel while antenna correlation is not considered, and the broadband SISO channel is composed of a flat Rayleigh channel. On this basis,the parameters which are suitable for the modeling of UAVs are selected through reasonable analysis and existing aeronautical channel parameters. And the reasonable model of UAV channel is established by using the correlation description method and SCM modeling method which is based on the geometric distribution. The UAV's MIMO channel which is established before are then described from the following aspects: time domain channel statistical characteristics, the spatial correlation of the channel and the channel capacity,etc. Finally, by using the hardware and software co-simulation method, the SCM-MIMO model based on geometric distribution is realized on the the Matlab simulation platform and the FPGA hardware platform, in the end, the statistical characteristics and the correlation of the hardware are analyzed.