Modeling, analysis, and simulation of nonfrequency-selective mobile radio channels with asymmetrical Doppler power spectral density shapes

What terrestrial and satellite land mobile radio channels have in common is that they are usually assumed to be nonfrequency selective. For such fading channels, a highly flexible analytical model is presented. Our model takes into account short-term fading with superimposed long-term lognormal variations of the local mean value of the received signal. It is assumed that the introduced complex stochastical process, which is used for modeling the short-term fading behavior, has a Doppler power spectral density with an asymmetrical shape. Closed solutions are presented showing the influence of asymmetrical Doppler power spectral density shapes on the statistical properties of the proposed channel model. A numerical optimization procedure is shown for the optimization of the model parameters in order to fit the statistics of the analytical model [amplitude probability density function (PDF), level-crossing rate (LCR), and average duration of fades (ADF)] to measurement results of an equivalent land mobile satellite channel for light and heavy shadowing environments. Finally, from the analytical model, an efficient simulation model is derived that enables the simulation of such realistic land mobile satellite channel scenarios on a digital computer.