Statistical characteristics of channel parameter for HF communication circuit

The design optimization of digital communication systems, using selective fading channels (such as HF and troposcatter), requires some knowledge of the statistics of the fading parameters of these media. The test results are presented of the phase jitter, signal-to-noise ratio, multipath spread and Doppler spread measurements on several approximate 8000 km HF digital communication circuits from 1975 to 1978, using the continuous wave and Bello´s real-envelope methods respectively. From these test results, two real-time channel evaluation techniques, the multitone envelope method and multitone complex envelope method, for real-time frequency selection systems of ionospheric radio circuits are presented