Fade measurements on the wide bandwidth HF channel


  • Robert Rifkin,

  • B. Dan Perry


This paper presents the results of HF channel fading measurements on 2000 and 3000 km midlatitude paths using a 1-MHz instantaneous bandwidth direct-sequence pseudonoise (DSPN) probing signal. The channel impulse response is estimated by correlating the received probe signal with a local DSPN reference. The channel is characterized in terms of the autocovariance and distribution functions of the received power. Bandwidth-dependent characteristics are obtained by Fourier transforming the measured impulse response and then applying appropriate filtering. The measured long-term wideband power statistics show a median standard deviation of 2–3 dB and median decorrelation times of 37 to 57 s. Both median fade depth and median incremental fade depth always decrease with increasing bandwidth.