| 摘要 |
PURPOSE:To receive always a stable data signal by switching the receiving state on a basis of detection results of the second and the third segments after detection of the first segment to make the tap coefficient set condition of an automatic equalizer accurate. CONSTITUTION:A code generating circuit CDG is provided which generates a bit string corresponding to a preliminarily determined artificial random pattern, and the output of this circuit and the parallel output of a shift register SRG are given to a collating circuit RFF such as a magnitude comparator or the like; and if they coincide with each other, ''1'' is generated as a coincidence signal from the circuit RFF, and an FFC FF8 is set to invert an output Q to ''1''. Consequently, if the coincidence signal is generated as the result of detection of the artificial random pattern of a segment IV after a detection signal DS is generated as the result of detection of a frequency spectrum peculiar to a segment III, the output Q of the FFC FF8 is set to ''1'' to transmit as a control signal CS, and this signal is used to switch the reception state to a state corresponding to a short training signal STS. |
