Macrocellular angle-of-arrival and delay propagation characteristics and their impact on smart antenna design and performance

Data relating to the angular and temporal distribution of the propagation channel in the mobile cellular frequency bands is critically important to the process of determining optimum smart antenna base station designs. A programme of work has been undertaken by Nortel Technology to develop a high performance multipath angle-of-arrival (AoA) measurement facility, the Aperture Analyser. The purpose of this facility is to gain information on the propagation channel for a variety of cellular applications. The equipment has been designed to facilitate a comprehensive measurement campaign and has the potential to address a wide range of applications and representative propagation conditions. The equipment has been trialed extensively for macrocellular applications in the 1800 MHz band in the UK and has enabled urban, suburban and rural environments to be characterised. The paper describes the measurement equipment identifying the key performance attributes and modes of operation. Results are presented illustrating AoA vs. time delay results for a variety of propagation environments. Analysis is applied to these examples to demonstrate the upper bounds on performance achievable by possible smart antenna system designs relative to a more conventional antenna configuration. For this discussion the uplink diversity gain is used as the measure of system performance.