On the reference signal parameters in the cross wigner-ville distribution based instantaneous frequency estimation method

Discussion on the reference signal (RS) and the related parameters in the recently proposed Cross Wigner-Ville distribution (XWVD) based method for the signal components instantaneous frequency (IF) estimation is presented. By a convenient choice of the reference signal, cross-terms are formed in such a way that the XWVD between the analyzed signal (AS) and a reference signal (RS) yields a scaled image closely resembling the IF laws of the signal components. Following strict geometrical rules that govern interferences and relying on a reference signal for providing a well localized point in time-frequency plane, the time-frequency coordinates of the component IFs can be calculated in an automatic procedure. The effects of the reference signal´s parameters on the method´s performance are discussed and examples are given for various choices of the RS´s parameters.