| 摘要 |
PURPOSE:To easily remove a noise component which has a high level higher than a reception threshold level by storing a noise level of every phase unit and then subtracting said noise level from a received reception level. CONSTITUTION:A reception side separate a noise in the same frequency band with a phase pulse signal from an AC voltage wave 6 prior to the transmission of a phase pulse signal, detects noise levels of respective phase units U1-U10 of channels CH1-CH20 for a specific number of cycles, and calculates and stores mean levels of noises of the respective phase units U1-U10. Then, the transmission of the phase pulse signal is started, and when the phase pulse signal of a hannel CH4 is received on the reception side together with a noise, data D'1-D'n of the phase units U1-U10 from the 1st cycle to the (n)th cycle and data D''1-D''n on standing noises 8 are collected, and the mean level of said noise is subtracted from the collected value. |
