Modeling and characterization of a body channel communication system

Body Channel Communication (BCC) is a short-range communication method that exploits the human body as medium to transmit electrical signals. BCC is very appealing for Wireless Body Area Network (WBAN) applications because it guarantees a much lower power consumption respect to RF communication, is less affected by signal leakage and external interference and is inherently secure since the signal remains confined in the proximity of the human body. In this thesis, a BCC system which exploits capacitive coupling is tested in terms of SNR, Total error rate and Packet error rate in different configurations. When a subject wears the receiver on bare skin or different tissues SNR ranges between 30 dB and 40 dB, whereas Total error rate is below 40%. A lumped parameter model is developed to investigate signal propagation in the human channel. Firstly, relying on the impedance vs. frequency measurements on different subjects and configurations, the contact of the device electrode and the body is studied. A MATLAB routine is implemented to fit the model parameters. The fitting absolute mean error is below 4° for the impedance phase and 30 Ω for the impedance module. Then, approximating the channel as a transmission line, the physics of body channel communication is assessed while evaluating the influence of the intrinsic parameters of the device and the electromagnetic properties of the living tissue.