In the paper, we consider the problem of simultaneous determining the structure of a probe signal varying in time and a one-dimensional transmission function, that characterizes the influence of object on the signal. The peculiarity of solution is that one does not need any special determination of the transmission function. Moreover, in the course of processing, one does not need to use any iteration procedures, which may simplify the treatment and reduce the time required. In order to determine the amplitudes and phases of the signal under investigation and the transmission function, one has to obtain four independent functional relations. To this end, one uses the modulating-spectral approach, that is, the input and output signals are additionally modulated in a certain way that somehow implies visualizing the phase. Besides, one should form the spectrums of the signals so that four independent intensity distributions are registered. The first intensity distribution is registered for tested signal without additional modulations, i.e., determined solely by the transmission function. The second distribution is for the signal undergone an additional modulation before passing the media, while the third one, on the contrary, is for the signal modulated afterwards. At last, the fourth distribution describes the signal undergone the both additional modulations. In principle, having the four functional dependencies for the concrete modulations, one can determine the spectral representations of the signal and the transmission function, i.e. their original structure.