Analysis of Scattering in Mobile Radio Channels Based on Clustered Multipath Estimates

Abstract

This paper presents the results of angle and delay measurements in physically nonstationary radio channels obtained in an outdoor urban environment. The multidimensional estimation data are obtained using a recently developed 3-D high-resolution channel sounder. The estimation results are compared with results obtained from a 3-D deterministic propagation prediction tool. For a better analysis, a hierarchical clustering method is presented that can separate and group the multidimensional estimation data into clusters. Measurements performed at a fixed position as well as along a trajectory are used to characterize the angular dispersion in both azimuth and elevation. The angular dispersion in terms of the rms cluster angular spread in both elevation and azimuth of the different clusters is analyzed over space and time and related to its physical scattering sources. Compared to the measurements, a large number of multipath clusters are missing in the predictions. Furthermore, it is observed from the measurements that different objects cause different angular spread values in azimuth and elevation. The results can be very helpful for the identification, improvement and calibration of deterministic propagation prediction models.

Scale Model Investigation of Mechanisms for Scattering From Office Buildings at 2 GHz

“…For outdoor radio links, scattering from buildings has been found to be a major source of multipath. While in-situ measurements have been used to characterize building scattering [3]- [11], only limited studies have attempted to identify the actual building features that give rise to the scattering [3], [4]. In view of the importance of scattering from buildings, it seems worthwhile to understand the physical mechanisms that give rise to it.…”

“…[3], [4]. The simplest approach to modeling surface scattering treats the surface as having normally-distributed continuous random height variation without corners [11]- [14].…”