Measurements and Characteristics Analysis of Millimeter Wave Channel Trough the Over-the-Horizon Marine Evaporation Duct

This study investigates the propagation characteristics of 25 GHz millimeter wave (mmWave) signals in maritime evaporation ducts through fixed-to-fixed point maritime channel measurements in the South China Sea. Utilizing high-performance equipment such as USRP X310 and 25 GHz converters, the research aimed to understand the impact of environmental factors on signal propagation. Key findings include slightly higher path loss (PL) values in the evaporation duct compared to line-of-sight (LOS) free space, indicating duct-enhanced signal propagation. The study also observed frequency-selective behavior and the influence of factors like water vapor absorption and sea surface roughness on PL. Continuous channel impulse response (CIR) snapshots were collected under various environmental conditions. Analysis revealed stable signal power at millisecond level, The variation period of received signal power is similar to that of ocean wave spectrum, which is in the level of seconds. The study provides valuable insights for the development of future maritime communication technology.