Parameter estimation algorithms for ionospheric channels

The principal parameters of a multipath channel are the delay and the gain coefficient of each path, and the number of significant paths. We develop a methodology for estimating path-delays and path-coefficients and applied it to the ionospheric channel estimation. Also, if path coefficients are stationary random processes, the power spectral density of the coefficients can be estimated from measured data of real channels. Finally, some parameter estimations for real narrowband HF ionospheric channels are shown, where several rays are detected with a Doppler spread about 0.2 Hz.