Link quality evaluation unit is very essential in recent digital data receiver
especially in time vary channel such as HF and mobile radio. It provides the adaptive
detector with the required information or parameters optimize its performance from the
power and rate points of views. These information parameters include the signal-tonoise
ratio, Doppler spread, channel severity and the estimate of the sampled impulse
response of the channel.
Efficient schemes for the estimation of HF channel were presented. The chosen
parameters are the Doppler spread, channel severity and the signal-to-noise ratio which
are the dominant ionosheric propagation parameters.
Computer simulation tests have been carried out to evaluate these estimators over HF
channel that has been simulated based on Waterson model. Results of computer
simulation tests have shown the ability of these estimators to track the variation of the
HF channel accurately and efficiently.