Multipath Problems in Radio Frequency Transmission Systems

摘要

The phase characteristics of incoherent multipath reflection between airborne and ground-based terminals was examined. Measurements were made on calm overwater paths at frequencies of 2.735 and 8.205 GHz. No significant differences in the measured phase spectra are noted for the two frequencies of measurement or with propagation direction relative to sea surface wave structure. The measured phase spectra decreases at a rate of 3 to 5 db per octave in the 100- to 1,000-Hz band. Maximum phase modulation indexes observed are 10 degrees rms phase deviation within the 100- to 2,000-Hz band. This phenomenon probably does not present an important limitation to data-link reliability. (Author)