Link Budget of a Ka-Band HAP-Based Communication System under Different Climatic Conditions in Different Seasons
A high altitude platform (HAP)-based communication system operating in the Ka-band (28/31 GHz band) is proposed as the "last mile" solution for providing broadband services to users of remote western mountain area in China. The atmospheric attenuations due to rain, gaseous absorption, tropospheric scintillation, and cloud are calculated under different climatic conditions in different seasons. The subscriber ground station is put in Chengdu, Sichuan province. The propagation data and prediction methods recommended by the radiocommunication sector of international telecommunication union (ITU-R) are employed. The mean monthly profile of air pressure, temperature, and relative humidity, range from 0 to 20 km, is obtained by interpolation and extrapolation of the data announced by the ITU-R bureau. The link budget analysis shows that, for specified service requirements and designed system parameters, the link budget varies greatly under different climatic conditions and slightly for the same climate in different seasons. Rain attenuation has the most detrimental effect on link performance.