Time-frequency derivation of periodic wide band probing signals
Thomas W. Parks, Michael S. Richman · 2002
An analysis of a discrete time-frequency distribution yields a new periodic wide band probing signal for use in unknown system identification. The derivation is based on the mathematical properties of the discrete Wigner distribution. Like the continuous distribution, the discrete version also satisfies the covariance property, meaning transformations in the time-frequency plane are equivalent to transformations in the time domain. By utilizing this property, the linearly swept frequency measurement is extended to discrete, periodic signals. The resulting probing signal possesses favorable characteristics such as a short illumination time requirement and good resistance to noise. The performance of the proposed probing method is compared with m-sequence methods and chirp signal methods.