Measurement of human exposure to LTE base stations present status and future challenges in measurement methodology

Spectral and code selective methodologies are presently used with regard to human exposure measurements at LTE base stations. Whereas the code selective technology requires decoding equipment, the spectral measurements uses standard spectrum analyzers. A thorough investigation, however, shows that the spectral measurement cannot be regarded as equivalent alternative to code selective measurement. This is due to the incapability of separating different cells. The situation becomes complicated, when the synchronization signals dominate the measured spectrum, because different transmission schemes concerning the MIMO antenna ports impede the assessment. These topics have not been addressed adequately in the present LTE annex of EN 50492, which therefore needs revision.