A low energy wireless body-area-network transceiver with scalable double-FSK modulation

Abstract

This dissertation presents a low energy wireless body-area-network (WBAN) transceiver system based on the fundamental studies on body channel communication (BCC), which uses human body as a communication medium. Previous BCC transceivers were not optimized for WBAN because the only phenomenological circuit/behavior models were used for the body channel analysis, which means there was not a clear understanding of the on-body electric signal transmission mechanism and the electrode interface on the human body. Moreover, they were unable to satisfy WBAN requirements such as energy efficiency, scalability of quality of service (QoS), interference mitigation, and network co-existence, simultaneously. To provide a clear understanding of the transmission mechanism on the human body, from Maxwell’s equations, the complete equation of electric field on the human body is developed to obtain a general BCC model. The mechanism of BCC consists of three parts according to the operation frequencies and channel distances: the quasi-static near-field coupling part, the reactive induction-field radiation part, and the surface wave far-field propagation part. The general BCC model by means of the near-field and far-field approximation is developed to be valid in the frequency range from 100 kHz to 100 MHz and distance up to 1.3 m based on the measurements of the body channel characteristics. The path loss characteristics of BCC are formulated for the design of BCC systems and many potential applications. In addition, the BCC characteristics via various electrode configurations are theoretically studied by means of polarization property of the electric field, and compare the theoretical analysis with the measurement results. Furthermore, the noise characteristics of the electrode interface on the human body are investigated with power spectral density (PSD) measurement. Based on it, the sensitivity analysis in BCC transceiver is obtained with noise matching condition which gives ...