Research On Ultraviolet Communication Performance In Low Visibility Weather

In recent years,heavy fog and dust weather have occurred frequently in North China and other regions,and a large number of aerosol particles are suspended in the air during these low-visibility weather conditions.These aerosol particles scatter with ultraviolet photons,which can change the direction of photon motion in the atmospheric channel,so as to realize the non-line-of-sight transmission of ultraviolet light signals.The impact of higher concentration of aerosol particles on the performance of UV communication in low-visibility weather is the key research work of this article.In order to study the non-line-of-sight ultraviolet communication in foggy weather,such as sand and dust weather in low visibility environment of communication performance,in view of the common experience of light attenuation model is not suitable for uv transmission model of atmospheric channel attenuation analysis,multiple scattering calculation is more complicated in short ultraviolet communication distance and low visibility environment problem,this paper proposes a new empirical attenuation model,and simplify the scattering phase function of asymmetric factor,at the same time diversity reception technology is introduced to improve the performance of ultraviolet communication.Firstly,the physical properties of several aerosol particles in low visibility weather were analyzed,and the empirical model of UV attenuation under low visibility weather was established based on Mie scattering theory,and the UV attenuation parameters of different aerosols at different concentrations were obtained.Secondly,the summation parameters of aerosol particle radius and corresponding particle size were used as data points to establish a simplified calculation method for the asymmetric factor of the scattering phase function in the multiple scattering transport model.Finally,a dual channel UV communication system is established by using diversity receiver technology.The path loss,bit error rate and communication distance of SISO system and SIMO system are analyzed respectively by using and improving Monte Carlo algorithm.Meanwhile,the influence of different factors on pulse broadening in single channel is analyzed.The results show that :1.Under the same visibility,the optical attenuation ability of several aerosols is radiation fog type,advection fog type,sand dust type and soot type in order from strong to weak.2.In the range of short-range communication,the path loss under high concentration channel is smaller than that under low concentration,while the communication distance beyond this distance gradually increases,and the path loss under high concentration channel is higher than that under low concentration.3.The path loss is reduced by about 2.5d B by the diversity receiving technique in dual set number.The bit error rate is obviously reduced and the communication distance is extended.In foggy weather,the enlargement of the maximum communication distance decreases with the increase of visibility.In dusty days,the enlargement of the maximum communication distance increases with the increase of visibility.