A simulation method for Doppler spectra

To evaluate the performance of modern modulation techniques suited for time-variant multipath propagation, it is necessary to simulate such channels by computer models. A time-variant multipath channel distorts a transmission link by frequency and time dispersion. While the simulation of time dispersion can be accomplished by a finite tapped delay line, the simulation of the frequency dispersion depends on the time variations of the channel, which are typically very slow compared to the sampling interval of the simulation and therefore, difficult to simulate. Before a new method for the simulation of Doppler spectra is presented, the theory of channel modelling and Doppler spectra is reviewed and known methods for the simulation of Doppler spectra and their disadvantages are discussed.