Digital vestigial sideband transmit system

PURPOSE: A system for digital VSB transmission is provided to obtain larger coded gain of additional data, and improve receiving performance related to ghost of channels by encoding additional data at the rate 1/2 and multiplexing with predefined sequence. CONSTITUTION: A system for digital VSB transmission includes an additional data processor, a multiplexer, a first encoder, an additional data symbol processor, a control signal generator, a first decoder, and a VSB transmitter, wherein a rate 1/2 convolutional encoder of the additional data symbol processor includes a first multiplexer(51) selectively outputting a feedback from a first register(52) or a feedback from a second register(55) according to a control signal, the first register storing the output of the first multiplexer for a regular time, an adder(53) adding a value to be inputted to upper bit to the output of the first register, a second multiplexer(54) selectively outputting the output of the adder or a feedback from the second register, the second register storing the output of the second multiplexer for a regular time, a third multiplexer(56) selectively outputting the output of the second register or a value to be inputted to lower bit according to a control signal, and a fourth multiplexer(57) selectively outputting the output of the third multiplexer or the value to be inputted to lower bit according to the control signal.