Patent ID: 8054891

Claim:
A method of processing a digital broadcast signal for transmitting the digital broadcast signal, the method comprising: Forward Error Correction (FEC) and Cyclic Redundancy Check (CRC) encoding enhanced service data to build at least one Reed-Solomon (RS) frame of the enhanced service data; encoding the enhanced service data in the at least one built RS frame at a coding rate of at least 1/2 or 1/4 to output symbols; forming a data group including the encoded enhanced service data, a plurality of known data sequences and place holder bytes for main service data, MPEG headers and RS parity data; removing the place holder bytes for the main service data and the RS parity data which are included in the data group and replacing the place holder bytes for the MPEG headers with the MPEG headers, and outputting enhanced service data packets; multiplexing the output enhanced service data packets and main service data packets including main service data; and interleaving the enhanced service data and the main service data of the multiplexed enhanced and main service data packets in the data group, wherein the data group, having the interleaved enhanced service data and the interleaved main service data, includes first segments, second segments and third segments, the second segments being positioned between the first and third segments, the first segments having enhanced service data and main service data, the second segments having enhanced service data and the plurality of known data sequences, and the third segments having enhanced service data and main service data, wherein the enhanced service data in the first, second and third segments are encoded by non-systematic RS encoding, the main service data in the first and third segments are encoded by systematic RS encoding, and at least two of the plurality of known data sequences have different patterns.