Path Gain and Channel Capacity for HAP-to-HAP Communications

High Altitude Platforms (HAPs), which are unmanned aerial vehicles (UAV) to provide communication services at high altitudes, are alternative cutting edge communication technologies which combine the benefits of satellite and terrestrial communication systems. HAP systems have several key benefits including simple deployment, reconfigurability, low operating costs, low propagation delay, high elevation angles, wide coverage, broadcast capability and mobility in several scenarios. In this study, we focused on a channel model analysis between HAPs to calculate the channel capacity for a HAP-to-HAP communication link using a model that takes into account the antenna radiation pattern, the effects of atmospheric gases, rain, and cloud/fog, and also the polarization mismatches of the transmitting and receiving antennas. With the simulation results, we demonstrated the path gain characteristics and the channel capacity of the high-altitude air-to-air channel for various scenarios depending on different antenna types, platform altitudes, carrier frequencies, etc. Lastly, we mentioned a future work representing a real-life use case which is also appropriate to apply this method.