UBC Theses and Dissertations
Characterization of ultrawideband radiowave propagation within the passenger cabin of a Boeing 737-200 aircraft Chuang, James Tzu-Ho
In 2002, ultrawideband (UWB) systems gained prominence in the field of radar, communications and sensor networks when FCC made their ruling on the unlicensed commercial use of the 3.1-10.6 GHz spectrum. Channel modeling for UWB thus became extremely important for the evaluation of newly proposed systems. Currently, based on the envisioned applications, standard channel models based on the Saleh-Valenzuela (S-V) model have been developed by two dedicated IEEE task groups, 802.15.3a and 802.15.4a for four environments: residential, office, outdoor and industrial. However, with increasing demand for wireless connectivity, wireless devices are being deployed in more areas that have not yet been well characterized. One such environment is the public transportation. In this thesis, we have made three major contributions. First, the identification of clusters is the essential first step needed for the extraction of S-V model parameters; however, this process is still being done through subjective visual inspections. Here, we remove that subjectivity and make the process more consistent by developing an automated cluster identification algorithm based on performing regression analysis on exponentially decaying clusters expressed in semi-logarithmic scale. Second, based on extensive measurements, we characterize the large-scale aspects of UWB propagation in the passenger cabin of a Boeing 737-200 aircraft; an environment that is fundamentally different from environment previously considered due to its confined volume, cylindrical structure and high passenger density. Several noteworthy aspects include: (1) the coverage within the passenger cabin is found to follow a chevron shape contour where it is the greatest along the aisle and the weakest around window seats which suggests that the path gain also depends on the seat location and (2) high passenger density can introduce significant excess path loss. Third, based on more extensive measurements, we model the small-scale aspects of UWB propagation which focused on the shape and duration of the channel impulse response and the small-scale fading of multipath components. In most cases, our results take the form of the parameters of the standard channel models and can be used directly for those planning to simulate, evaluate and deploy UWB systems in the aircraft environment.
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