Abstract: A signal transmission apparatus for minimizing a PAPR in an OFDM communication system. A subband divider divides L information data subcarrier signals into M subband signals. An additional information inserter inserts into the L information data subcarrier signals P additional information subcarrier signals. A dummy sequence inserter inserts the dummy sequence into a subband in the position. An IFFT block initially generates first and second OFDM symbol signals using M dummy sequence-free subband signals and M dummy sequence-inserted subband signals. A controller determines a sign bit value and an address bit value of the additional information when a PAPR value of the first OFDM symbol signal exceeds a predetermined PAPR threshold, and then performs a control operation of inserting the dummy sequence into a subband in a position corresponding to the address bit value so that the second OFDM symbol signal is transmitted over a downlink.