Human body communication performance simulations
1University of Oulu, Faculty of Information Technology and Electrical Engineering, Department of Communications Engineering, Communications Engineering
|Online Access:||PDF Full Text (PDF, 4.1 MB)|
|Persistent link:|| http://urn.fi/URN:NBN:fi:oulu-201606092482
|Publish Date:|| 2016-06-15
|Thesis type:||Master's thesis (tech)
Human Body Communication (HBC) is a novel communication method between devices which use human body as a transmission medium. This idea is mostly based on the concept of wireless biomedical monitoring system. The on-body sensor nodes can monitor vital signs of a human body and use the body as a transmission medium. This technology is convenient for long durations of clinical monitoring with the option of more mobility and freedom for the user. In this thesis, IEEE 802.15.6-2012 physical (PHY) layer for the HBC was simulated. Simulation model is following the standard’s requirements and processes. The human body was taken as a transmission medium and simulations, which follow the HBC standard, have been carried out. For the purpose of simulations, MATLAB is used as a platform to test and run the simulations. The constants and variables used in the simulations are taken from the IEEE 802.15 working group for wireless personal area networks (WPANs). The transmitter model and the receiver model have been taken from the standard, with changes done in it for performing the simulations on the PHY layer only. The simulations were done keeping in mind the dielectric properties of the outer layer of a human body, i.e., the dielectric values for human skin are noted and their corresponding values were used in the mathematical calculations. The work done here presents a transmitter and receiver architecture for the human body communication. The minimum data rate being 164 kbps and the transmitter being designed around the 21 MHz center frequency has achieved some outputs which are worth looking. The channel models used in this simulator are HBC channel and AWGN (additive white Gaussian noise) channel. It was observed that when signal was passed through AWGN channel, noise was added uniformly over the signal, while in the HBC channel signal strength is directly proportional to the transceiver ground sizes. In conclusion, the size of the ground terminals plays a critical role for the signal quality in the HBC simulator. The results in this thesis show that pathloss has certain linearity with the distance. The pathloss is calculated for different parts of the body with higher loss for structure with higher amount of bone, and vice versa. It is observed that in the HBC channel there are four factors with high impact on the system. These are the distances between the transceiver in air and on body while the other two are the sizes of the transceiver grounds. The size of the transmitter ground has been deemed very significant for the HBC from the simulations results. The four factors show high impact on the HBC channel. The signal strength is highly effected with the change in these four characteristics. From the simulation results it is evident that the HBC channel show a 15 to 20 dB deviation when compared to AWGN channel. The Eb⁄N0 for BER level at 10^(-3) for AWGN channel is 10 to 11 dB while for HBC it is around 27 dB showing a significant difference in the results.
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