Abstract: A resource allocation method for an orthogonal frequency division multiplexing access (OFDMA) system is provided. The resource allocation method includes dividing a frequency band occupied by a predetermined number of OFDM symbols into a plurality of subbands and determining the number of diversity subchannels, each of which comprises at least two time-frequency resources respectively included in different subbands, and the number of subband selective subchannels, which comprise time-frequency resources that are not included in the diversity subchannels; and generating the diversity subchannels and the subband selective subchannels according to the determined numbers and allocating a physical channel comprised of a generated subchannel to a user in a cell. Accordingly, diversity is enhanced without reducing the freedom of selection of a subband.