Study on the impact of the body shadow effect in wireless channels through dosimetry measurements

The body shadow effect (BSE) is defined as the underestimation in logged data by personal exposimeters (PEMs) when the PEM is worn by the user (on-body location) that obstructs the direct signal path between the measuring device and the radiation source. This study considers the levels of exposure at 2.4 GHz, measured by PEMs, as a received signal composed of three fading components: path loss, local mean fading, and small scale fading. Two cases are analyzed: when the PEM is worn by the user, and when the PEM is situated 1 m away from the user. Although the lognormal distribution presents the best suitability in the transmitter-to-receiver and transmitter-to-body channels, the fading components present particular features in shadowing conditions: the local mean fading signal does not change drastically, but the instantaneous levels, of small scale fading have a greater variation, especially when in proximity to the radiation source. The different features of the fading components in the shadowed and non-shadowed exposure data, is a reason to question the effectiveness of the correction factors in mitigating the BSE uncertainty.