On the efficiency of time-varying channel models

We consider the form of a physically motivated simple one path time-varying channel in the time-varying impulse response, time-frequency characterization and time-scale characterization settings. The focus, in general, is to determine which setting allows for the most efficient (i.e., sparse) discrete channel representation. We measure how well the discrete representation reconstructs the channel when a limited number of discrete coefficients are available and compare the result among the channel models.