Performance Analysis of LOS THz Systems under Misalignment and Deterministic Fading

Abstract: Line-of-sight (LOS) wireless communication at terahertz (THz) frequency bands is envisioned to play a major role in defining next-generation wireless technologies. This work analyzes the performance of a potential LOS THz system experiencing propagation loss and misaligned antenna beams. The THz channel particularities are discussed in terms of deterministic path loss, molecular absorption effect and stochastic fading due to antenna pointing errors. Assuming phase shift keying (PSK) modulation schemes, simplified analytical expressions are approximated for computing symbol error rate (SER) of the proposed THz system. Monte Carlo simulations are applied to verify theoretical model accuracy over various transmission distances and misalignment scenarios. The derived SER formulas match simulation results for Signal-to-noise ratio (SNR) above 35 dB at transmission distance up to 100 m and antenna displacement jitter variance of 0.05 $m^2$. In general, the theoretical model mismatch does not exceed 2 dB for lower SNR levels.