Aerial reconfigurable intelligent surface (ARIS), is an intelligent
reflecting surface (IRS) mounted by unmanned aerial vehicle (UAV), represent a
promising candidate for assisting device to device (D2D) millimeter wave
(mmWave) communication in temporal and urgent situations, e.g., open-air
events. IRS can efficiently mitigate the high blockage impact on mmWave
propagation signal in base station to device use case. But, the scenario of D2D
communication is different as both the transmitter (TX) to ARIS and the ARIS to
receiver (RX) links are highly susceptible to be blocked due to the low height
of the TX and RX. Consequently, in this paper, the impact of human bodies
blockage on ARIS aided D2D mmWave communication is studied. Firstly, we assure
the effectiveness of using ARIS in this network to significantly enhance its
performance, then, the effect of ARIS height on the blockage occurrence and
system performance is investigated to find out the optimum height. Our results
proves that ARIS highly mitigates the blockage, reduces it by 85%, comparable
to the case without it. Moreover, a high increase in system spectral
efficiency, 1.2 bps/Hz, can be guaranteed, if ARIS is configured at optimum
height