Signal-to-Noise Ratio Analysis of a Noisy-Channel Model for a Capacitively Coupled Personal Area Network

We investigated a noisy-channel model for a capacitively coupled personal area network (CC-PAN) with megahertz-frequency signals. The new channel model describes the influence of a power line connected to transceivers. Using the model, we analyzed characteristics of a CC-PAN channel in detail. The signal-to-noise ratio (SNR) for the CC-PAN channel can be calculated from the model. It is also shown that the SNR can be enhanced by using a common-mode choke. We also give a physical interpretation of the mechanism of the SNR enhancement. Furthermore, we propose design guidelines to obtain a large-SNR CC-PAN system. The validity of our model and analyses are confirmed by experimental results.