An evolutionary spectrum approach to modeling non-stationary fading channels

To evaluate mobile communication systems, it is important to develop accurate and concise fading channel models. However, fading encountered in mobile communication is usually non-stationary, and the existing methods can only model quasi-stationary or piecewise-stationary fading instead of general non-stationary fading. To address this, this paper proposes an evolutionary spectrum (ES)-based approach to modeling non-stationary fading channels. Our ES approach is more general than the existing piecewise-stationary models and is capable of characterizing a general non-stationary fading channel that has an arbitrary ES (or time-varying power spectral density); our ES approach is parsimonious and is also able to generate stationary fading processes. As an example, we show how to apply our ES approach to generating stationary and non-stationary correlated Nakagami-m fading channel processes. Simulation results show that the ES of the channel gain process produced by our ES-based channel model agrees well with the user-specified ES, indicating the accuracy of our ES-based channel model. Copyright (c) 2011 John Wiley & Sons, Ltd.