The application proposes an apparatus and a method for maximazing decoding performance by performing the soft decision decoding utilizing the inverse fast Hadamard transform (IFHT) even for block codes where the generator matrix does not include a basis of a Walsh code. In the apparatus, symbol position information for relocating each reception symbol is determined utilizing the block code generator matrix information having k rows and n columns and an IFHT size information for performing an IFHT for the reception symbols, each reception symbol is relocated as an input of an IFHT unit according to the determined symbol position information, the relocated symbols are input and the IFHT is performed for the symbols; and a codeword of the block code, which has a maximum correlation value from among result values obtained by performing the IFHT, is output as a decoding signal.