Dear Naser,
Yes, the vertical spacing is the sacing between antenna elements that are mapped to one port.
-The parameter antenna_element_horizontal_spacing specifies the spacing between antenna elements (ports) which are assumed to be in horizontal dimension. Antenna arrays are assumed to be uniform.
-The position of each antenna element is calculated in +channel_gain_wrappers\TR36873_Fading_3D_Channel.m
Regards,
Fjolla