Apparatus and method for guard interval inserting/removing in an OFDM communication system

A method for generating an OFDM symbol for transmission in an OFDM communication system, the method comprising the steps of:

• copying first data at a first interval and second data at a second interval in a data row inputted to be transmitted;
• generating a first guard interval symbol in which unique words are filled, the unique words having a constant amplitude and a non-periodic auto-correlation characteristic;
• generating a second guard interval symbol in which the copied first data are filled;
• generating a data interval symbol in which the inputted data row is filled;
• and
• generating a third guard interval symbol in which the copied second data are filled;
• generating the OFDM symbol, which is comprised of the first guard interval symbol, the second guard interval symbol, the data interval symbol, and the third guard interval symbol;
• wherein the inputted data row is divided into a first data row and a second data row continuing in sequence, and one of the first interval and the second interval at which the first data are copied is located at a rearmost portion of the first data row.

An apparatus for transmitting an OFDM symbol in an OFDM communication system, the OFDM symbol including a guard interval and a data interval, the apparatus comprising:

• a guard interval filling means for copying data at a predetermined interval in a data row inputted to be transmitted, and filling the copied data in the guard interval set in advance in the input data row;
• and
• a selection means for selectively receiving an output data row outputted from the guard interval filling means and unique words having a constant amplitude and a non-periodic auto-correlation characteristic, and outputting the OFDM symbol in which the unique words are inserted in the output data row;
• wherein the guard interval is located before the input data row, and the unique words are located in the middle of the guard interval.