说明：  Multipath fading channel simulators are essential components of wireless systems physical layer simulations. This white paper presents a MATLAB-based approach to multipath fading channel simulation. Section II presents an overview of popular methodologies for the simulation of multipath fading channels. Two effects must be simulated: the time selectivity of the channel (Doppler spreading) due to motion, and the frequency selectivity (time spreading) due to resolvable multipath components. Simulation approaches are reviewed for both these tasks....