Distributed Antenna System for Improving THz Coverage Inside Rooms

Abstract

At THz frequencies, the limited penetration through interior walls resulting from significant transmission attenuation losses likely confines the propagation mechanisms to inside rooms. Distributed antenna systems (DAS) being a choice to maintain reliable 100 Gbit/s wireless links are employed in this paper to study the THz coverage in the presence of multiple humans. The study environment is a non-cubic 3D office room model of 7 x 7 x 3 m 3 at our Institute of Digital Signal Processing (DSV) as shown in Fig. 1 (a) . For this purpose, we employ up to five 3D models of both male (1.76 m high) and female (1.70 m high) clothed bodies designed in a 3D computer graphic software tool and then imported as an object (computation intensive with 48,090 polygons/faces) to ray-tracing tool. Upon entering the office room, the human models follow certain trajectories till they reach their respective workplaces. Moreover, the gait motion phases (in a total walking cycle) along with a predefined step size for each human body model is taken into account. Assessing the coverage, the transmitting access point antenna is placed at different locations (i.e., middle and all four corners) in the room and the coverage maps are then generated at two chosen heights of the receiving antenna grid as depicted in Fig. 1 (b) . The chosen RXPs are 0.25 m from the floor when taking into account the worst-case coverage whereas in case of table top terminals these possess a height of 0.75 m. There are 72,900 receiver points (RXPs) covering the entire office room, required to study the frequency selective fading. The details of the human body models together with the antenna positions in addition to simulation parameters as well as material parameters at 300 GHz will be conferred in the full paper.