Patent ID: 7729437

Claim:
A method for transmitting a signal using a low density parity check code in a mobile communication system that transmits the signal through a plurality of transmission antennas by space-time coding the signal, the method comprising: forming a lifting low density parity check matrix by expanding values of elements in the low density parity check matrix to a sub-matrix corresponding to a number of the plurality of transmission antennas; coding the signal to be transmitted using the lifting low density parity check matrix; serial to parallel converting the coded signal; and transmitting the coded signal through the plurality of transmission antennas, wherein, if the values of the elements in the low density check matrix are “1”, each of the values of the elements is expanded to a matrix selected from permutation matrices formed by exchanging rows of an identity matrix, and wherein at least one of the elements having values of “1” in a row of the low density parity check matrix is expanded to a sub-matrix including 2×2 identity matrix.