Digital broadcasting system and method of processing data

A digital broadcast transmitter of processing digital broadcast data, the digital broadcast transmitter comprising:

• a first randomizer configured to randomize mobile service data;
• a first encoder configured to perform first Reed-Solomon (RS) encoding on the randomized mobile service data;
• a group formatter configured to form first data groups including the first RS-encoded mobile service data and transmission parameters;
• a second randomizer configured to randomize header data in mobile service data packets that include data of the first data groups;
• a second encoder configured to perform second RS encoding on the mobile service data packets having the randomized header data;
• and
• an interleaver configured to interleave data of the second RS-encoded mobile service data packets to output second data groups.