Improving The Accuracy Of Characterizing Wireless Communication For Body Area Networks

In recent years, with the development of wireless medical instruments and thespeeding up of aging, Body Area Wireless Communication (BAWC) attracts more andmore attention in the academic community and industry. The essential differencebetween BAWC and traditional wireless communication is the environment wherewireless communication is taking place, while the existence of human bodyundoubtedly increases the complexity and uncertainty of wireless communication.Many attempts have been made so far to characterize wireless transceivers andcommunication for body area networks (BANs). This PhD thesis, under such abackground, is intended to present the characterization theory for BANs and propose thetechnologies which can improve accuracy of characterization for BAWC. The maincontributions are listed as follows:1. Statistical Learning Theory (SLT) is used to characterize human body specificityand its effect on the body surface radio propagation. The optimal parameters forprediction model and kernel functions are obtained by employing global optimization.Finally, we draw the conclusion that obesity poses risks to the body-surface wirelesspower transmission.2. The spatial properties of on-body radio propagation have been characterizedusing a K-weight-based spatial autocorrelation model. Results demonstrated that, forUltra-wideband (UWB) and narrowband radio propagation in the anechoic chamber,more accurate locations are needed for measurement repeatability due to lower values ofautocorrelation. It is also noted that accurate characterization of Root Mean Square(RMS) delay spread via on-body measurement at UWB frequencies is almostimpossible due to the low confidence value in the Z-score calculation. Analysis doesindeed show some striking advantages of applying this new model to existing on-bodyradio propagation characterization approaches; results also show the potential ofapplying this model to other propagation environments.3. An accurate and sharp band notch performance has been obtained using theelectrical coupling between radiating patch and parasitic element of the Tapered slot Antenna. On the other hand, a planar inverted-F antenna with periodic patternedstructures is proposed, new multiband design mechanism has been applied to traditionalPIFA to meet WLAN and/or WiMAX standards. The proposed design scheme andfollow-on PIFA antenna are very helpful in designing other quasi-PIFAs which takeexisting/potential multiband wireless communication standards into account.