A wireless communication system is disclosed. A method for performing a radio access in the wireless communication system includes dividing an available frequency band into a plurality of subbands, generating a plurality of frequency domain sequences from a plurality of data symbol sequences by independently performing a Fourier transform process in each of the subbands, independently mapping each of the frequency domain sequences to a corresponding subband, generating one or more transmission symbols by performing an inverse Fourier transform process on the plurality of frequency domain sequences mapped to the available frequency band, and transmitting the one or more transmission symbols to a receiver.