| 摘要 |
PURPOSE:To decrease crosstalk by measuring a crosstalk characteristic among all pair signal lines in a telephone system where some telephone sets are connected to a home bus comprising plural pair signal lines and measuring all the crosstalk characteristic of the mutual pair signal lines, and selecting and using a pair lines based on the result of the measurement. CONSTITUTION:In a telephone system where a control signal and a voice signal from a controller 1 are sent to telephone sets through a home bus comprising plural pair signal lines 21-25, the crosstalk characteristic among the pair signal lines 21-25 is measured (10) over all the combinations, the result of measurement is stored (11) and any of the pair signal lines 21-25 is selected in the order of less crosstalk based on the stored crosstalk by a changeover selection means 12. The crosstalk measuring means consists of a changeover switch 10a, an amplifier 10b, a filter 10c an an A/D converter 10d. |
