Experimental evaluation of space diversity schemes at a base station in a microcellular environment at 900 MHz and 1800 MHz

摘要

The aim of this paper is to evaluate experimentally the performance of different space diversity schemes at the base station end in a semi-urban microcellular environment. The receiving antennas were separated in horizontal, vertical or compound direction in order to provide decorrelated signals. The superior received signal was chosen based on the selection combining criterion. A measurement campaign was conducted at both appropriate frequency bands (900 MHz and 1800 MHz) for mobile telecommunications. Measurements were performed along the route containing both line-of-sight (LOS) and non-line-of-sight (NLOS) paths. The measured data was analyzed and signal cross-correlations, signal mean levels of individual receiving branches and diversity gains of different receiving antenna separations (horizontal, vertical and compound) were evaluated. According to the measurements, low signal cross-correlations and reasonable diversity gain at the base station end can be achieved even with ≤4 250L?separation of the receiving antennas in any direction at both 900 MHz and 1800 MHz frequency bands. The obtained results also showed that horizontal, vertical and compound space diversity gains are almost the same. Hence, spatially small and variable antenna configurations for space diversity reception can be applied at the wall installations in a microcellular environment.