The power line carrier modem based on the analysis of the transmission characteristics

摘要

The power line carrier modem which used a band 450 kHz or less is going to be standardized by the Echonet Consortium. Since many devices are connected, the noise of a power line is large and its transmission characteristic is also bad. In this paper, the transmission characteristics is analyzed by modeling of the impedance of connected devices and the power line cable, and it is examined whether the transmission of 9.6 kbps would be possible. As a result, the impedance of connected devices become low with several ohms near a resonance point, so it has the frequency characteristic that differs for every device. Moreover, we proposed MESA-SS that is prevented the transmission-quality degradation by the impedance depreciation in an unspecified frequency, it is improved about 6 dB compared with the conventional SS, and the bit error rate are 10{sup}(-5) or less in the pseudo power line.