Measured Channel Parameters for the Disturbed Wide-Bandwidth HF Channel
MITRE CORP BEDFORD MA
Pagination or Media Count:
Recent measurements have been made of the wideband HF WBHF channel impulse response over a high-latitude auroral path using the MITRE experimental WBHF test facility. A nominal instantaneous bandwidth of 1 MHz was used for the majority of the tests. These tests took place from 14 March through 1 April 1992 over a path from Sondrestrom AFB, Greenland to Bedford, Massachusetts, a distance of approximately 3100 km. The measurements were made using a direct- sequence pseudonoise DSPN channel probe with a chip rate of 1024 k samples per second. Channel impulse response samples at increments of 500 nanoseconds in delay were derived by correlating the received signal with a set of local DSPN references uniformly spaced in delay over a delay range of 2 ms. The channel was sampled in this fashion at a rate of up to 62.5 samples per second, resulting in the ability to observe Doppler spreads and shifts of up to 31.25 Hz. From these measurements the channel scattering function, rms 2 sigma Doppler spread, rms 2 sigma Delay spread, Doppler shift, and rms 2 sigma spread factor were calculated. In addition, for the first time, the impulse response correlation along the delay axis was calculated. These latter measurements support the use of an uncorrelated scattering hypothesis in modeling the disturbed WBHF channel.
- Radio Communications