http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Rain fade mitigation technique time diversity for future millimeter wave satellite communication systems in tropical region
International Islamic University Malaysia
Department of Electrical and Computer Engineering
The current persistent escalation of satellite communication usages has led to frequency spectrum congestion. The majority of present satellites are being operated in Ku-band (11 GHz) frequency, and it can be fathomed that the next generation of satellite communication systems will have to be operated at higher frequencies as high as V-band. Rationally, higher frequency offers higher system bandwidth, which supports higher data rates. In addition, it requires smaller size receiver antenna which offers easier installation. However, higher frequency is more sensitive to propagation impairments, mainly: due to rain attenuation. The challenges are more noticeable in tropical regions, where the rainfall rate is higher in this region. Rain is the major factor that typically limits the implementation of higher frequencies for satellite communication links in this region. This research intends to explore Time Diversity as a viable rain fades mitigation technique to encounter such problems. The scheme involves retransmission of information utilizing multiple channels with certain time delay. Twelve months of Ka-band (26 GHz) and V-band (38 GHz) microwave link rain attenuation data were collected at Universiti Teknologi Malaysia, Skudai, Johor Bahru. The study involves the conversion of rain data to attenuation levels. Attenuation levels were processed into daily, monthly and annual cumulative distribution functions. Time-shifts were applied using the collected data and signal improvement gains had been ascertained. Substantial amounts of diversity gain had been detected from the plot of Time Diversity distribution as the time-shift increased. A scheme was proposed to convert terrestrial link data to applicable satellite-Earth link and was validated against ITU-R Recommendation. The performance of Time Diversity technique for possible satellite link operating in the tropics was also quantified. Mathematical models of Time Diversity gain for Ku-band, Ka-band and V-band were derived in this study. This is an encouraging finding for a new theory of future satellite broadcasting systems that could provide higher durability from rain fade but at the expense of real-time viewing.
Thesis (MSCE)--International Islamic University Malaysia, 2016.
Includes bibliographical references (leaves 121-142).