Antenna diversity technique for enhanced ultra wideband radio performance in body-centric wireless networks

In this paper preliminary studies for analysis of antenna diversity in ultra wideband (UWB) on-body channel are carried out. Measurements are performed in both an anechoic chamber (no multipath reflections) and in a typical indoor environment (dense multipath surroundings) on a human subject for static and dynamic cases. Various diversity techniques are demonstrated and investigated to highlight the benefit of incorporating such methods in enhancing the overall system performance by increasing the reliability of the link and hence success reception rate. Diversity gain (DG) is calculated for five different on-body channels by plotting cumulative distribution functions (CDF) and it is found that diversity gain value is very low for chamber due to no reflections from surroundings as compared to indoor environment. Also in indoor environment and chamber, diversity gain is lowest for line-of-sight (LOS) case. There are significant benefits of diversity techniques for nonline-of-sight (NLOS) case as compared to LOS cases due to low power imbalance and low correlation coefficient between the branch signals.