Narrowband cross-correlated model for dispersive signals and its use for phase delay estimation

Traditional narrowband signal cross-correlated model cannot be used directly for phase delay estimation for dispersive signals, especially when the dispersion is strong. The reason lies that the phase item in the cross-correlation function of dispersive signals contains non-linear components. However, current cross-correlation model is assumed with linear phase, which is not in accordance with the fact of dispersive signals and will lead to big error for phase delay estimation. A new cross-correlation model is established by introducing a quadratic component in the phase item. The estimation error is much smaller when the proposed model is employed for phase delay estimation for dispersive signals. At the same time, the proposed method is more robust than current model, for instance, it is insensitive to the variation of signal bandwidth.