Patent ID: 8201050

Claim:
A broadcast transmitting system comprising: a group formatting unit for mapping mobile service data into at least one region of a plurality of regions within a data group and adding a plurality of known data sequences to the data group; a deinterleaver for deinterleaving data in the data group; a first multiplexer for multiplexing mobile service data packets including the deinterleaved data with main service data packets including main service data; an interleaver for interleaving data in the multiplexed data packets; a trellis encoding unit for trellis encoding the interleaved data, wherein at least one memory included in the trellis encoding unit is initialized at a start of at least one of the plurality of known data sequences; a second multiplexer for multiplexing the trellis-encoded data with segment synchronization data and field synchronization data; and a modulator for modulating a broadcast signal including the multiplexed data, wherein at least two of the plurality of known data sequences in the broadcast signal differ from each other in length, wherein at least two of the plurality of known data sequences in the broadcast signal are spaced 16 segments apart, wherein one of the plurality of known data sequences in the broadcast signal includes a first M-symbol sequence and a second M-symbol sequence that have a first pattern, and the rest of the plurality of known data sequences in the broadcast signal include an N-symbol sequence that has a second pattern other than the first pattern, and wherein N is greater than M.