Channel Characteristics and Link Budget Analysis for 10-60MHz Band Implant Communication

抄録

Channel modeling is a vital step in designing transceivers for wireless implant communication systems due to the extremely challenging environment of the human body. In this paper, the in-to-on body path loss and group delay were first analyzed using an electric dipole and a current loop in the 10-60MHz human body communication band. A path loss model was derived using finite difference time domain (FDTD) simulation and an anatomical human body model. As a result, it was found that the path loss increases with distance in an exponent of 5.6 for dipole and 3.9 for loop, and the group delay variation is within 1ns for both dipole and loop which suggests a flat phase response. Moreover, the electric and magnetic field distributions revealed that the magnetic field components dominate in-body signal transmission in this frequency band. Based on the analysis results of the implant channel, the link budget was analyzed. An experiment on a prototype transceiver was also performed to validate the path loss model and bit error rate (BER) performance. The experimentally derived path loss exponent was between the electric dipole path loss exponent and the current loop path loss exponent, and the BER measurement showed the feasibility of 20Mbps implant communication up to a body depth of at least 15cm.