Indoor channel characterisation for a wearable antenna array at 868 MHz

Correlated channel measurements were made for an array of 8 bodyworn antennas moving in the indoor environment at 868 MHz. First and second-order statistical methods were used to investigate the effect of antenna positioning and human body interaction on the fading experienced by each antenna element. Average received signal strength was reduced for antenna placements lower on the body. The maximum variation in received signal power was observed for receiver positions on the upper torso. The results also show that reductions in crossing rates are experienced for wrist-worn antennas. A selection combination diversity configuration was shown to significantly reduce fade depths by as much as 6 dB for four on-body elements when compared to a single branch