Smoothed calculation of interference from an array of cells

Abstract

Presents a model developed to calculate the intersystem interference (ISYSI) between two different systems that operate in adjacent areas. The model is simple and employs an integral over a field of interfering sources located with a certain density within the entire area in question. Several parameters have been studied, including distribution of interferers (mobiles/base stations) in the interfering system, area and geometry of the interfering system, and the effects of adding cells to the interfering system. The integral of the source density is normalized to the desired number (and strengths) of the sources. The integral does not have a closed form but the numerical integration is straight forward. The results of this study can be used to define the guard zone between the two adjacent systems. The results are compared with those derived from Vasquaz and Montalvo (1997) and H'mimy and Kilvia (1997). Qualitatively, this method gains in simplicity, allows for not only the real-life irregularity of shape and layout of interfering cells but also for modeling different source densities. The detailed structure of the cells in the field of interferers becomes irrelevant. With this integration technique we average over realistic distributions and movements of the interferers in a manner that yields an approximation at least as good as any other and that allows easy adjustments for changing traffic patterns, calculation of "worst case" scenarios, etc. Under the same cell geometries and layout as that described in Vasquaz and Montalvo the results obtained by using the two methods agree closely.