Apparatus and method for transmitting/receiving broadcast data in digital broadcasting system

A method for receiving broadcast data including main data and additional data in a digital broadcasting system, comprising:

• receiving from a transmitting antenna a broadcast data encoded with symbols having a plurality of levels, wherein the plurality of levels includes extended levels, and wherein the broadcast data includes a main data and an additional data;
• dividing the broadcast data into a first portion of the broadcast data having bypass levels and a second portion of the broadcast data;
• deciding whether the second portion of the broadcast data includes data mapped to extended levels;
• differentiating the levels of the second portion of the broadcast data;
• and
• outputting modulation values for the additional data based on the levels of the second broadcast data.

An apparatus for transmitting broadcast data in a digital broadcast system,

• comprising:
• a transmitter for transmitting broadcast data including a main data and an additional data, wherein the transmitter includes a detector configured to decide whether levels of the main data encoded with symbols having a plurality of levels belong to a first portion of the main data having bypass levels or a second portion of the main data;
• and
• a mapper configured to map the main data symbols of the second portion of the main data to extended levels by using modulation values of the additional data.

An apparatus for receiving broadcast data in a digital broadcasting system,

• comprising:
• a receiver for receiving from an antenna broadcast data including a main data and an additional data, wherein the receiver includes a detector configured to decide
• whether a broadcast data encoded with symbols having a plurality of levels may be divided into a first portion of the broadcast data having bypass levels and a second portion of the broadcast data, and
• whether the second portion of the broadcast data includes data mapped to extended levels;
• and
• a demapper configured to output modulation values of the additional data based on the levels of the second broadcast data.