Performance dependence of non-line-of-sight ultraviolet communications on atmospheric parameters of the ultraviolet channel

Non-line-of-sight (NLOS) ultraviolet (UV) communication systems are rapidly gaining popularity as an effective means of data transmission over long distance. UV communication systems offer huge unlicensed spectrum with low-cost implementation. However, the performance of the UV system depends strongly on atmospheric parameters of the UV channel, such as temperature, pressure, turbulence and altitude, between the transmitter and the receiver. In this paper, we evaluate the link performance of the NLOS UV communication under these varying atmospheric parameters. Specifically, the impact of temperature, pressure and altitude on the Rayleigh and Mie scatterings are investigated, as the scatterings provide the basis for transmitting information over the NLOS UV channel. As the turbulent atmospheric channel causes fluctuation in the received signal intensity, a closed-form expression for the average channel capacity as a function of temperature and pressure for a given transmit power is also derived. The atmospheric turbulence is modeled by a Gamma-Gamma distribution. Simulation results show that the received power decreases with increasing atmospheric pressure, while the data rate increases with increasing temperature.