Tropospheric Scatter Propagation and Equipment Performance Results Obtained on a System in Korea

A six-hop radio system employing line-of-sight, diffraction, and tropospheric propagation modes, in the 4.4- to 5.0GHz band, has been installed in Korea. Received carrier levels and teleprinter error rates were recorded and analyzed, and the results extrapolated to predict minimum performance for 99 percent of all hours of the year. The carrier level measurements for the troposcatter links indicated more extreme seasonal variations than predicted by the NBS method. In measurements of the teleprinter error rates on the troposcatter links, it was found that for both dual and quadruple diversity, the advantage of pre-detection over postdetection combining was 4 to 6 dB for a teleprinter character-error-rate of 1 in 10 000.