PURPOSE: To reduce data errors of a character broadcast signal due to group delay in a low frequency range by a filter for code interference cancellation.

CONSTITUTION: The decoded video signal from a video signal input part 1 is inputted to an A/D conversion part 2 to sample the character broadcast signal superposed in a vertical blanking period by using the signal from a timing signal generation part 11, thereby converting the signal into digital data. The data are delayed by one clock through a delay circuit 3, multiplied by a multiplier 4 on the basis of error quantity data 10 after error correction when an exclusive OR circuit 9 outputs a signal '0', added by an adder 5 to the digital data from the A/D conversion part 2, and sliced by a slicer 6 and outputted. The exclusive OR circuit 9 processes the data detected with the output signal of the slicer by a last bit detection part 7 and a before-last bit detection part 8 and outputs '0' when its input data are both '1' or '0'.