This article proposes the unified short-time Wigner-Ville distribution (USWD) and explores its various properties, which is a generalized integral transform suitable for time-varying signals with varying features. Recognizing the complexity involved in this transformation and aiming for practical applications, we focused our research on a specific case, denoted as SWDL. In this study, we derived the Heisenberg's uncertainty principle for SWDL and presented its discrete form. Furthermore, we investigated the potential applications of SWDL in the analysis of stepped-frequency linear frequency modulation (SF-LFM) signals.