| 摘要 |
PROBLEM TO BE SOLVED: To provide a multi-channel FSK modulator and demodulator for power-line communication system which suppress communication channel noise and attenuation or distortion of communication signals caused by multi-path fading, and improve phase response of power-line communication signals. SOLUTION: In a power-line communication system with a digital-to-analog converter which converts digital signals to analog signals and transmits them via a power line, a multi-channel FSK modulator has multiple modulators 1 to 4 and a mixer 5. The modulators modulate multi-channel transmission data which have been preset to different frequencies, and the mixer mixes these modulated signals and outputs the resultant signals to the digital-to-analog converter. By use of multi-channel FSK modulation, when the state of one or more channels is not good, if at least one channel receives information correctly, communication without errors is realized. |
