Investigation of radio propagation and macroscopic diversity in indoor microcells at 1700 MHz

Abstract

An empirical propagation model and the performance of a two-branch macroscopic diversity configuration for indoor microcells are presented. The model is based on measurements made in three different cell types classified according to the indoor environment. Analysis of measured signal strength levels has shown that macroscopic diversity techniques can be used to reduce the link margin for the required 99% area coverage in each cell type. The reduction is dependent of the fading distribution and the maximum achievable rate at which the best path can be selected. The gain with selective macroscopic diversity varies from 4 dB in a cell with high overall propagation attenuation to 10 dB in an open area cell type with lower propagation attenuation. This reduction is obtained when the selections between base stations are made at intervals shorter than 25 cm and the short-fading component is eliminated. The gain can be as high as 12 dB, if all fading is taken into account and the selections are made at intervals shorter than 4 cm.<>