Disconnection probability improvement by using artificial multi reflectors for millimeter-wave indoor wireless communications

In order to solve a key problem with multi-Gbps transmission in the 60 GHz band-communication interruption by human body crossing, this paper proposes a method to create more reflected waves by installing artificial reflector(s) in two-dimensional arrangements; we show that it reduces the disconnection probability from 80 to 20% (with one artificial reflector) and from 80 to 5% (with two reflectors). The interruption by human crossing is modeled and locations of transmitters and receivers are freely set on any node of a 50 centimeter grid (room sizes are defined by IEEE802.11ad) to get statistically meaningful data. Computer simulations are carried out with various TX and RX antenna HPBWs (Half Power Beam Width), several receiver sensitivities corresponding to 3 Gbps to 0.5 Gbps transmission and assuming a fixed TX antenna direction and a beam-forming receiver antenna that can track the incoming reflected wave(s) in the case of LOS (Line of sight) path interruption. The required minimum reflector radius and disconnection probability can be estimated from the chart described herein given the diagonal dimension of the room and data rate as inputs. By using the chart, the improvement in disconnection probability achieved by installing reflectors can be estimated easily. The improvements by the proposed method are generally applicable to similar indoor communications environments.