An Efficient Method for Avoiding Shadow Fading Maps in System Level Simulations

In system-level simulations of wireless communication systems, shadow fading is commonly modeled by spatial autocorrelation. Currently, shadow fading values are generated using a shadow fading map, which rasterizes the region of interest. This map is commonly generated at its full extent, although only a small part of it may be needed. In this paper we propose an approach for generating shadow fading maps that is also capable of generating single shadow fading values. This is achieved by generalizing the shadow fading map to an N-dimensional array of correlated random variables, which is generated by applying a coloring transformation, in form of linear filtering, to an array of uncorrelated random variables. Moreover, in the paper we will also discuss the feasibility of this approach and its application for generating correlated variables over a continuous curve in space.