A method for inserting parity into an FCH is disclosed. A method for inserting parity into a frame control header includes channel-encoding, by an additional channel encoder, a frame control header bit applied to a legacy encoder, and generating an additional codeword, and mapping the codeword generated by the legacy encoder and the additional codeword to subcarriers. This method inserts parity into the FCH, and defines a new FCH, such that it extends an FCH coverage simultaneously while maintaining a compatibility with a legacy system. Also, it may add additional energy to a legacy FCH or may give a coding gain to the same legacy FCH, such that it can extend information transferable using reserved bits of the FCH.