An Integrated Propagation-Mobility Interference Model for Microcell Network Coverage Prediction

This paper presents a new interference model for microcellular networks which integrates radio propagation parameters and user terminal mobility. This model uses a parameter denoted the “interference to noise ratio” (INR) to obtain a simplified description of mobile link outage contours as a function of the location of the fixed and mobile radio ports. The INR is used to demonstrate that microcell networks are more interference limited than macrocell networks, and thus are more affected by user terminal mobility. Expressions are derived for the INR and user terminal cell radius distributions. It is shown that in microcell systems a significant proportion of terminals may not be able to meet a contiguous coverage criterion, and that closer microcell spacing can reduce rather than improve the coverage quality. Examination of cochannel and adjacent channel reuse ratios in DCA microcell systems suggest that the closer frequency reuse is primarily responsible for these coverage effects. Monte Carlo simulations are used to test the analytical theory. These results may form the basis of a design methodology for microcell systems.