Virtualized terminal utilizing terahertz band radio waves for Beyond 5G: Link budget analysis

In B5G mobile communication, ultra-high-speed UL transmission of over 100Gbps is expected to lead to the realization of a cyber-physical system [1]. Although the UL channel capacity can be improved by increasing the number of UE transmitting antennas and adopting the UL MIMO scheme, the advantage conferred by having more antennas cannot be maximized due to the fact that the maximum transmission power of a UE is limited. Furthermore, although THz band radio waves are expected to be used for high-speed data transmission, it is difficult to obtain a communication distance similar to that of conventional mobile communication systems due to the large propagation loss. In order to realize multi-antenna uplink MIMO for UEs, we have proposed a novel UE configuration referred to as the "virtualized terminal", in which UE antennas are distributed to the relay devices, a UE transmits UL signals in the THz wave band, and relay devices convert the signals to mmW band radio signals and relay them to a BS. In this paper, the communication distance of the virtualized terminal is evaluated by the link budget calculation using a practical configuration and the parameters of the RF components. Furthermore, we show the THz antenna gain of each THz link which satisfies the required C/N and the maximum data transmission speed of the virtualized terminal with uplink MIMO.