Method Analysis For The Measurement Of Electromagnetic Field From LTE Base Stations

This paper is focused to analyze the proposed methods for in-situ measurements of electromagnetic fields transmitted by LTE base stations. One of the methods is based on measurements of physical broadcast channel PBCH using basic spectrum analyzer whereas the other method is based on measurements of the reference signal RS using a decoder. Both alternatives are proposed to be used for extrapolation to the maximum electromagnetic field exposure level at full base station traffic load. The analysis is conducted with respect to instrument requirements accuracy and time requirements. Different instrument settings of the spectrum analyzer and their impact on the measurement results is analyzed and discussed. Measurements using the spectrum analyzer method overestimate the electric field strength compared with the LTE decoder method in 2661627 70 of all measurement cases in this work. All spectrum analyzer based measurements conducted in the main beam of an antenna at distances of less than 100 m were within 20 compared with the decoder results. Measurement results obtained in a reflective environment show that both methods are affected by fading but significant deviations between the two methods indicate that the spectrum analyzer method is more sensitive to frequency selective fading.