A VSB communication system comprises a VSB transmission system and a VSB reception
system. The VSB transmission system multiplexes a coded MPEG data and a coded supplemental
data having a null sequence inserted therein, with required multiplexing information
included in a field synchronization signal or in a supplemental data according
to a number of the supplemental data packets being transmitted. The VSB reception
system detects the required multiplexing information from the field synchronization
signal or the supplemental data and decodes the multiplexed data by using the null
sequence and the detected multiplexing information, as well as demultiplexes the
multiplexed data into the MPEG data and the supplemental data.