海面空-空无线信道特征

针对海上远距通信场景,基于无人机之间的无线通信链路,对接收功率进行实际测量。在大尺度路径损耗方面,采用对数距离线性模型进行拟合,分析海上远距空-空无线信道特征,获取路径损耗指数,并采用射线跟踪方法进行仿真验证,通过仿真所得信道冲激响应在多径时延和功率方面分析产生接收功率快速变化的原因。分析结果表明,近岸的多径反射会造成接收功率的波动,并且会造成路径损耗的升高。利用三种分布函数对测量数据进行分布拟合,分析海面和近岸两种通信条件下空-空无线信道的小尺度分布特征。测量分析结果表明,小尺度特征受陆地反射影响明显,在距离陆地较远的海面呈现高斯分布特征,而在近陆地处未呈现典型分布特征。

Characteristics of air-to-air wireless channel in sea scenario

For the remote communication scenario of UAV(unmanned aerial vehicle) at sea, the received power was measured on the basis of the wireless communication link between UAVs. In terms of large-scale path loss, the logarithmic distance linear model was used to fit the measurement data. The characteristics of remote air-to-air wireless channel at sea were analyzed, and the path loss index was obtained. The ray tracing method was used to simulate and verify the measurement results. Through the simulation of channel impulse response, the reasons for the rapid change of received power were analyzed in terms of multipath delay and power. The analysis results show that the multipath reflection in the nearshore causes the fluctuation of the received power and increases the path loss. Three kinds of distribution functions were used to fit the measured data, and the small-scale distribution characteristics of air-to-air wireless channel under sea surface and inshore communication conditions were analyzed. The analysis of the measurement results shows that the small scale characteristics are significantly affect by the land reflection, showing Gaussian distribution characteristics at the sea surface far from the land, but not typical distribution characteristics near the land.