Selecting a modulation technique to conserve power when power supplied to an entire power line communication system falls below a threshold power

摘要

A comparison section determines whether the amount of electric power acquired by a power management section is less than a predetermined threshold. A selection section selects, based on the determination result from the comparison section, at least one modulation/demodulation scheme among a plurality of kinds of modulation/demodulation schemes so that power consumption of modulation/demodulation operation is smaller when the amount of electric power is less than the predetermined threshold than when it is not less than the predetermined threshold. A power line communication function section transmits a control signal indicating the modulation/demodulation scheme selected by the selection section to the power line and performs modulation/demodulation operation under the selected modulation/demodulation scheme.