Impact of beam misalignment fading on modulation selection and diversity order in terahertz band drone communications

Official URL: https://dx.doi.org/10.1109/BALKANCOM65827.2025.11185975

The Terahertz (THz) band (0.1-10 THz) is a candidate band for 6G and beyond non-terrestrial networks (NTNs) because of the large bandwidth and data rates it inherently provides. However, with carrier frequencies in the THz range, the communication beams in the THz band are razor-sharp, making them prone to misalignment, and resulting in fading due to beam misalignment (BM). In this paper, considering various modulation schemes, we examine the effect of BM fading on the average bit error rate (BER) for THz drone-to-drone (D2D) communications. Additionally, we analyze the diversity order of the average BER under BM fading as a joint function of frequency ranging from the microwave frequency range up to free-space optics, and realistic D2D transmission distances, leading to valuable insights into the design of practical drone communication systems for 6G and beyond NTNs.