Patent ID: 8446968

Claim:
A mode detecting method performed by an orthogonal frequency division multiplexing (OFDM) receiving apparatus, the mode detecting method comprising: detecting a first mode of a received signal by using first delay signals obtained by delaying the received signal, and first correlation values of the received signal; and detecting a second mode of the received signal by using second delay signals obtained by delaying a first correlation value corresponding to the first mode from among the first correlation values, and the first correlation value corresponding to the first mode, wherein the detecting of the second mode comprises: selecting one of the second delay signals according to the first mode; calculating an accumulation value for the second mode by subtracting and adding the selected delay signal and the first correlation value; and detecting the second mode based on the calculated accumulation value, and wherein the detecting of the second mode based on the calculated accumulation value comprises: receiving the accumulation values; obtaining a first maximum value through an i-th maximum value according to a size order of the received accumulation values, wherein i is an integer of 2 or above; obtaining a first maximum value index through an i-th maximum value index with respect to the first through i-th maximum values; and increasing a count of the calculated accumulation value by 1, after obtaining the first through i-th maximum value indexes.