Patent ID: 8040924

Claim:
A digital broadcast transmitter, comprising: a pre-processor configured to pre-process enhanced data, wherein the pre-processor comprises: a frame encoder configured to form an RS (Recd-Solomon) frame, wherein the RS frame includes a plurality of rows including the enhanced data, each of the rows have same size, wherein the frame encoder is further configured to perform an RS encoding for each of columns of the RS frame to add parity data for each of the columns, and perform a CRC (cyclic redundancy check) coding to add CRC checksum data for each of the rows of the RS frame; wherein the enhanced data is included in a first data group, the first data group including first sequence of predetermined data and second sequence of predetermined data, the first sequence of predetermined data having a first length, the second sequence of predetermined data having a second length, wherein the first length is longer than the second length; a multiplexer configured to multiplex enhanced data packets including the enhanced data with one or more main audio and video, AV, data packets including main AV data; a data interleaving unit configured to interleave data in the multiplexed enhanced and main AV data packets; a trellis encoder configured to have at least one memory and trellis-encode the interleaved data, the at least one memory being initialized by initialization data at a beginning of a sequence of the predetermined data; and a data transmission unit configured to insert synchronization data into the trellis-encoded data, modulate the trellis-encoded data having the synchronization data, and transmit the modulated data.