Fast beam searching concept for indoor Terahertz communications

The Terahertz (THz) technology is a promising solution to future multiple Gigabit indoor communications because of its huge available bandwidth. To compensate the high path loss in the THz range, a phased array can be applied at both transmitter and receiver. The correct Angle of Arrival (AoA) and Angle of Departure (AoD) estimation is a prerequisite for maximizing the phased array benefits. The conflict between precision and computational effort, however, is difficult to balance. This paper introduces a fast and practical concept for the AoA and AoD estimation in 2 steps. In the first step, a preliminary estimation is carried out at a lower frequency via exhaustive scanning. After that, the precise angle is estimated at the actual frequency for the data transmission. An initialization protocol is formulated which determines the proper antenna configurations for the data transmission. This concept has been evaluated in a simple scenario using ray tracing simulations. The evaluation shows a satisfactory estimation precision.