RADIOFREQUENCY MAPPING OF AN OMNIDIRECTIONAL ANTENNA IN AN OUTDOOR DISTRIBUTED ANTENNA SYSTEM

Abstract

Some members of the general public have safety issues on the sources of non-ionizing radiation found in their environment. This study aims to produce a radiofrequency map to visualize exposure from an omnidirectional antenna in an Outdoor Distributed Antenna System (ODAS). First, field measurements are done in order to obtain the power density levels around the antenna. The highest power density level measured, which is 3.45 mW/m^2, is just 0.07 % of the reference level set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) for the exposure of the general public to radiofrequency radiation. A map was generated by using Ordinary Kriging as a spatial interpolation method on measured power density values. Cross-validation was done in order to find an optimal search radius to be used in estimating the unknown power densities. Error values were calculated for different search radii, where results show that the error values are lowest at 1m (Mean Absolute Error: 34.13%; Root Mean Squared Error: 44.41%; Mean Absolute Percentage Error: 37.76%). A radiofrequency map was then generated for a search radius of 1m.