Vsb transmission system

PURPOSE: A VSB(Vestigial Side Band) transmission system is provided to reliably transmit data even in a low ratio of signal to noise by adding 1/2 Convolutional Encoder having a state transition compatible with mapping of a TCM coder. CONSTITUTION: A VSB transmission system includes a 1/2 Convolutional Encoder, a 2/3 TCM coder and a signal mapper. The 1/2 convolutional encoder outputs 1 input bit as a first output bit by bypassing the input bit and outputs the input bit as a second output bit using a plurality of delay devices, adders and multipliers. The 2/3 TCM coder receives the two output bits from the 1/2 convolutional encoder, outputs the first output bit as a third output bit after bypass, outputs the second output bit as a fourth output bit after bypass, and outputs the second output bit as a fifth output bit after delay and addition of the second output bit. The signal mapper maps the third, fourth and fifth output bits.