DTV transmitting system and method of processing broadcast data therein

A digital television (DTV) transmitting system comprising:

• a first randomizer configured to randomize enhanced data bytes;
• a byte to bit converter configured to convert the randomized enhanced data bytes into bit units, thereby outputting enhanced data bits;
• an encoder configured to encode each of the enhanced data bits at a code rate of 1/H and to output the encoded enhanced data bits in symbol units, wherein H>1;
• a symbol interleaver configured to interleave enhanced data symbols output from the encoder according to the following equation:
• (i)={S×i×(i+1)/2}modL,
• wherein 0≦i≦L−1, L≧B, L=2n, n and S are integers, and B is a number of symbols being inputted to the symbol interleaver;
• a symbol to byte converter configured to convert the interleaved enhanced data symbols into byte units, thereby outputting enhanced data bytes;
• a group formatter configured to map the converted enhanced data bytes into data groups and to add known data sequences and signaling information to each of the data groups;
• and
• a second randomizer configured to randomize MPEG header data bytes of enhanced data packets including data in the data groups.