In view of the uniform distribution of the mobile communication environment with 3D scattering clusters,a statistical channel model for 3D spatial domain is constructed in this paper.In the macro-cell communication environment covered by directional antennas,the constructed model is used to estimate the parameters of the spacetime channel in the multipath fading channel,and the probability density functions ( PDFs) of the angle of arrival ( AOA) and the time of arrival ( TOA) are derived for the forward channel link in the multipath fading channel.In addition,the Doppler shift ( DS) caused by the movement of mobile stations ( MSs) is also derived,and the influences of both the spatial channel parameters and the main lobe width of directional antennas on the constructed model are analyzed.When the scattering objects around MSs are assumed as the Gaussian and exponential density models,the constructed model is more suitable to describe special mobile communication environments.The numerical simulation results show that the channel parameters estimated by using the proposed model are consistent with the theoretical and actual communication environments,which makes up for the limitations of the existing statistical channel models of three-dimensional scattering clusters.