Apparatus and method for transmitting/receiving signal in a communication system using low density parity check code

An apparatus for transmitting a signal in a communication system using a Low Density Parity Check (LDPC) code, the apparatus comprising:

• a controller for determining a number of ‘0’s to be inserted in information data according to a first coding rate to be applied when generating the information data into an LDPC code, and determining a number of ‘0’s to be removed from the LDPC code;
• a ‘0’ inserter for inserting ‘0’ in the information data according to control of the controller;
• an LDPC encoder for generating the LDPC code by encoding the ‘0’-inserted signal according to a first parity check matrix;
• a ‘0’ remover for removing the inserted ‘0’ from the LDPC code;
• a modulator for modulating the ‘0’-removed signal according to a modulation scheme;
• and
• a transmitter for transmitting the modulated signal.