To realize transmission with a high throughput regardless of use of an inexpensive terminal equipment of conducting delay control with high accuracy without the use of a high speed operating clock.

A transmission delay between the center equipment and a card modem is measured at the center equipment, delay control variable data to correct the transmission delay are informed to the card modem, a timing equalizer of a modulation section of which is provided with a buffer 48 and an FIR filter 49 to delay a transmission timing of an incoming transmission signal, the buffer 48 is used to apply delay control to the incoming transmission signal by a time equivalent to the count of the operating clock and a tap coefficient W of the FIR filter 49 is varied to shift the transfer characteristic in parallel in a direction of a time base within a range less than one period of the operating clock so as to control a phase of the incoming transmission signal.