Statistical characterisation for a mobile bodyworn personal area network in an indoor multipath environment at 868 MHz

The narrowband fading experienced by a mobile wireless personal area network was analyzed using first and second order statistics. Line of sight (LOS) and non-LOS conditions were considered for three indoor environments: anechoic chamber, open office area and hallway. Parameter estimates for the Nakagami-m, Rice and Rayleigh distributions were obtained using maximum likelihood estimation and competing models were indexed using the Akaike Information Criterion. Overall, the Nakagami-m cdf best described fading for bodyworn operation with 60% of measured channels following this distribution. Multipath fading played an important role in channel statistics with the maximum recorded m value for a bodyworn receiver being reduced from m = 24.0 (back right position) in NLOS anechoic conditions to m = 0.98 for LOS in the open office area. The coherence time, obtained using second order statistics, was greater for multipath environments compared to anechoic conditions.