Empirical Model Including the Statistics of Location Variability for the Over-Rooftop Path in the 32 GHz Band

This paper proposes a propagation prediction model including the statistics of location variability for over-rooftop path in millimeter-wave suburban environments. The predictive model derived from the measurement was developed to analyze the propagation characteristic of the signal according to the distance within the area of a millimeter-wave band or future fifth-generation service band. The measurement was carried out using a radio wave characteristic measurement system called the channel sounder, and the signal transmitted to the air was captured to make the received signal level data. The measurement system was constructed to predict spatial propagation characteristics by transmitting and receiving a signal with a 500 MHz bandwidth, and this system was capable of predicting characteristics of a signal that varied with space and time by capturing wideband multipath signals. Measurements were performed in a small town covered with low-rise commercial restaurants or houses. The transmission signal propagated through the rooftops of low-rise houses on average 10 meters high. Their multipath signal arrived at a receiving station located under the roof of the house through reflection, diffraction, and scattering mechanisms. The change in the signals due to the variation in location was measured up to a distance of about 500 meters from the transmitter. The basic transmission loss prediction model with a probability density distribution was analyzed and interpreted based on these measurements. In practice, it was necessary to statistically model for path loss according to the characteristics of the location due to the various environment changes, such as buildings and roads. The proposed prediction model derived from the measurement data reflects the propagation impact on over-rooftop paths in a small town and includes the statistics of location variability in line-of-sight and non-line-of-sight regions.