Modeling and Prediction of Millimeter Wavelength Channels

The demand for high capacity data communication is increasing continuously and rapidly. More Network-based multimedia applications such as Internet protocol Television (IPTV), video on demand (VoD), voice over Internet protocol (VoIP), and other broadband services are emerging. Due to congestion in the lower frequency bands many of the services may use millimeter wavelength bands. A good understanding of the propagation impairments at millimeter wavelength is important for designing systems with a targeted quality-of-service (QoS) and availability. Radio systems utilizing frequencies above about 10 GHz suffer from attenuation due to rain. Attenuation due to vegetation can severely degrade system performances as well. Estimation of the different time dynamic propagation impairments is essential for designing reliable and efficient communication systems. Depending on the current channel conditions such systems can adapt the transmission methodology to offer the required QoS and maximize the system throughput. The design of such mitigation technique requires knowledge of the different dynamic propagation impairments affecting the signal. The research conducted in this study is on modeling and prediction of propagation effects at millimeter wavelength channels. The focus is on propagation effects between 20 60 GHz with emphasis on signal attenuation and fading due to rain and vegetation. The study has led to development of a new space-time rain attenuation model which can be used for simulating multiple correlated rain attenuation time series. Four years of measurement data from a star-like network was used in the analysis. Based on the spatial and temporal correlation of rain attenuation, a model for generating correlated multipath taps during rain for broadband fixed wireless access (BFWA) employed in dense urban area was developed. In addition, using available measurements the effect of rain on the performance of BFWA was investigated. Duration statistics of rain attenuation are important when evaluating fade mitigation techniques (FMT) and estimating system outages. A study