Abstract: The present invention comprises a method for characterizing a multi-path signal transmission in transmitting a plurality of signals with a plurality of cyclic fields each including a plurality of horizontal scanning periods wherein some of the scanning periods are vertical blanking periods. The method comprising the steps of: (a). transmitting periodically in a plurality of the scanning periods in one of the fields at least two reference signals each with a different predefined signal characteristics; (b). receiving the plurality of signals including the reference signals; and (c). processing the received signals including the received signals of reference signals for detecting a multi-path channel delay of the signal transmission.