Delay time estimation using Hilbert transform and new extrapolation procedure

We present a new method for estimating the delay time of a minimum-phase system with delay. It is based on the Hilbert transform relationship between the log magnitude and the phase of a minimum-phase system. An extrapolation procedure for the frequency characteristics is required to describe a discrete causal system, which corresponds to the actual continuous system. The algorithm for the extrapolation is improved to stabilize the frequency characteristics, and further, bi-directional extrapolation procedure is presented.