Modelling of UHF radiowave signals within externally illuminated multi-storey buildings

A reliable model for UHF radiowave signal propagation into and variability within buildings is required to aid in the planning of cellular mobile radio systems serving portable transceivers. However, no such model has been presented in the literature to date and, with the imminent introduction of cellular mobile radio into New Zealand, a study of this problem has been undertaken with the aim of developing a model suitable for New Zealand buildings and situations. Two initial phases of this study have been completed in which suitable equipment and data collection and analysis procedures were established by conducting measurements at 927 and 851 MHz in a single building and at 851 MHz in another, dissimilar building where there was a line-of-sight path to all but one floor in both buildings. A preliminary model investigation using the data from unobstructed floors has shown that the measured cumulative probability density function of the received signal on a floor is best modelled by the Suzuki (Rayleigh plus log-normal) distribution and that the median signal level is not overly dependent on floor height.