INTELLIGENT WEATHER AWARENESS TECHNIQUE FOR MITIGATING PROPAGATION IMPAIRMENT AT SHF AND EHF SATELLITE NETWORK SYSTEM IN A TROPICAL CLIMATE

This paper presents an Intelligent Weather Awareness Technique (IWT) based on fuzzy logic to achieve optimum signal quality when the impact of weather attenuations become manifest in Earth-satellite link. An adaptive measure of a decision support system is adopted using the point rainfall rate to predict rain-induced attenuation over three locations in the tropical region of Nigeria based on Moupfouma rain rate and attenuation model. In order to impact good Quality of Service (QoS) in the overall design of satellite communication networks, considerable efforts have to be made, such as the use of appropriate forward error correction codes, the choice of modulations and the range of uplink/downlink power controls. The IWT interacts with the input parameters to optimise the Signal to Noise Ratio (SNR) values while the input parameters are varying. The results show that in all three locations considered, a minimum fade margin of about 12 dB on the uplink and similar to 8 dB on the downlink may be allowed at the 99.5% availability for a worst case scenario at Ka-band. Analysis based on SNR and consumed power at the same weather conditions confirms the suitability of introduction of fuzzy logic for optimum availability of good QoS in a weather impaired satellite system. The overall results would provide tolerance margins needed for better QoS, especially during bad weather in the study locations.