Subcarrier allocation apparatus and method, subcarrier de-allocation apparatus and method in OFDM system

A method for allocating data to be transmitted to a plurality of orthogonal subcarriers in an orthogonal frequency division multiplexing (OFDM) system, the method comprising:

• a) mapping, by a subcarrier allocating apparatus, a data subcarrier into a logical index, the logical index being formed by data subcarriers only;
• b) generating, by the subcarrier allocating apparatus, an intermediate index by modular operating the logical index;
• and
• c) converting, by the subcarrier allocating apparatus, the intermediate index into a physical index by inserting a null subcarrier being inserted as a guard interval into the intermediate index, the physical index indicating a location of a substantial subcarrier within a symbol.

A subcarrier de-allocating method for de-allocating data transmitting data from a plurality of subcarriers in an orthogonal frequency division multiplexing (OFDM), the method comprising:

• a) determining, by a subcarrier de-allocating apparatus, an effective subcarrier using an intermediate index generated by removing a null subcarrier from a current physical index which indicates a location of a substantial subcarrier within a symbol;
• b) obtaining, by a subcarrier de-allocating apparatus, the number of pilot subcarriers on left and right sides of the effective subcarrier;
• and
• c) obtaining, by the subcarrier de-allocating apparatus, a substantial logical index from the intermediate index by performing a given operation based on the number of pilot subcarriers obtained in b).