无人机空中OFDM光通信链路性能研究

基于无人机空中光正交频分复用(OFDM)通信模型链路的误码性能理论和仿真研究,综合考虑服从对数正态分布的大气湍流模型和服从瑞利分布的指向误差模型对通信系统的影响,采用高斯-厄米特积分方法得出了通信系统链路误码率的闭合表达式。在此基础上,仿真分析了发射端光束发散角、符号速率、子载波数和接收孔径大小与系统误码率的关系。仿真结果表明,在弱湍流条件下,发射端激光存在可使链路误码性能达到最优的光束发射角,湍流强度的改变对最优光束发散角的影响不大。光OFDM系统能够满足无人机间通信速率为吉比特级的光通信要求,并且通信时接收端的孔径尺寸不宜增大,该结果对通信链路的优化设计有一定的参考意义。

Research on The Performance of UAV Aerial OFDM Optical Communication Link

Theoretical and simulation studies were performed on the link error performance of UAV aerial optical orthogonal frequency division multiplexing communication model. Considering the influence on the communication system of atmospheric turbulence model obeying lognormal distribution and directional error model following Rayleigh distribution, Gaussian-Hermitian integral method was used to calculate the closed expression of link error rate of communication system at the same time. Based on this, the relationship between the beam divergence angle, the symbol rate, the number of subcarriers, the size of the receiving aperture and the system error rate was analyzed with simulations. The results show that under weak turbulence conditions, the transmitter laser has a beam emission angle which can optimize the link error performance, the relationship between the number of subcarriers and the bit error rate was greatly affected by the transmitted optical power, and the aperture size of receiving end of the communication should not be increased.