I. Introduction
Whereas the radio channel below 100 GHz is already well investigated for typical indoor scenarios [1]–[3], little is known about the radio channel above 100 GHz. In the D-band, ranging from 110 to 170 GHz, the 60 GHz available bandwidth suffers less than the 60 GHz mmWave frequency band from atmospheric absorption [4]. The D-band could be used for applications requiring ultra-high bandwidth [5] such as data kiosks [6], fixed wireless access [7] and virtual reality [8].