Digital broadcasting system and method of processing data

A method of processing a broadcast signal in a broadcast receiver, the method comprising:

• receiving the broadcast signal including first broadcast data encoded at a code rate, wherein the first broadcast data are multiplexed with second broadcast data, wherein the first broadcast data and the second broadcast data have a different robustness level, respectively, and wherein the broadcast signal does not include a null data packet;
• demodulating the received broadcast signal;
• decoding the first broadcast data in the demodulated broadcast signal;
• and
• de-randomizing the decoded first broadcast data.

A broadcast receiver for processing a broadcast signal, the broadcast receiver comprising:

• a tuner to receive the broadcast signal including first broadcast data encoded at a code rate, wherein the first broadcast data are multiplexed with second broadcast data, wherein the first broadcast data and the second broadcast data have a different robustness level, respectively, and wherein the broadcast signal does not include a null data packet;
• a demodulator to demodulate the received broadcast signal;
• a first decoder to decode the first broadcast data in the demodulated broadcast signal;
• and
• a first de-randomizer to de-randomize the decoded first broadcast data.