Digital broadcasting system, method, and data structure

The present invention is related to digital VSB transmission / reception system, in particular, the present invention transmits known data inserted into the defined groups known to the transmitting / receiving side in a specific location in the data area in which transmission data is enhanced. And it is possible to by means of the known data receiving side for demodulation or equalization process, improve the reception performance in a channel change is severe or mild to the environment noise. VSB, data bases, group