Beamforming and Transceiver HW Design for THz Band

The new spectrum available in the millimeter-wave (mmWave) and Terahertz (THz) bands is a promising frontier for the future wireless communications. Propagation characteristics at these frequencies imply that highly directional transmissions should be used to focus the available power to a specific direction. This is enabled by using tightly packed large-scale antenna arrays to form narrow or so called pencil beams both at the transmitter and the receiver. This type of communication is, however, quite sensitive to imperfections of the transceivers, resulting in beam pointing errors and lost connection in the worst-case. This paper investigates the impact of such errors, originating from the local oscillators in terms of phase noise, which is a major impairment with high center frequencies. We explore the impact of these effects with different transceiver architectures, illustrate the beam shape properties, and quantify their impact on the system performance for different modulation schemes in terms of error rates. Specifically, we model the phase noise both as Wiener and Gaussian distributed to characterize the impact of phase noise on the beam accuracy and system performance.