Fading characteristics of indoor off-body communications with multiple-antennas at the base station

In this paper, the first- and second-order fading characteristics of diversity reception techniques used for indoor off-body communications are investigated. The work considered a body worn transmitter situated at either the chest, waist or wrist of a user and a hypothetical 5.8 GHz base station equipped with multiple receive antennas. In particular, diversity specific statistics for selection, equal gain and maximal ratio combiners operating in Nakagami-m fading conditions were used to model the statistics of the small-scale fading experienced output of the combiner. It was found that adding additional branches significantly reduced level crossing rates at lower signal levels. Moreover, the theoretical diversity specific probability density and level crossing rate equations provided an excellent fit to all of the combined envelopes analyzed in this study.