Provided is a radio communication apparatus capable of always obtaining
the optimum error rate characteristic when an LDPC code is used for an
error-correcting code. In the apparatus, a temporary bit insertion
section (101) inserts a temporary bit into a position equivalent to that
of the systematic bit corresponding to a variable node having the largest
number of connections with a check node in the Tanner graph corresponding
to a check matrix in a transmission bit string and outputs the generated
bit string to an LDPC coding section (102), The LDPC coding section (102)
performs LDPC coding on the bit string inputted from the temporary bit
insertion section (101) by using the check matrix and obtains an LDPC
code word composed of the systematic bit and a parity bit. The LDPC code
word is outputted to a temporary bit removal section (103).