METHOD FOR SYNCHRONIZING FREQUENCY OFFSET OF WIRELESS LAN SYSTEM USING OFDM METHOD

摘要

PURPOSE: A method for synchronizing a frequency offset of a wireless LAN system using an OFDM(Orthogonal Frequency Division Multiplexing) method is provided to correct a phase within a short time by performing the first and the second phase error correction processes using a shot training sequence and a long training sequence. CONSTITUTION: A conjugating process is performed between short training sequences adjacent to a received preamble. A hexa value is decided by comparing a real number part and an imaginary number part to a stored value of a lookup table(30). A cosine value and a sine value are decided by comparing the hexa value to a value of the first NCO(Numerical Controlled Oscillator) table(41). A phase is corrected by applying the cosine value and the sine value to two long training sequences of the preamble. A phase offset is obtained by using the conjugate between the corrected long training sequences and the hexa value is added thereto. The cosine value and the sine vale are decided by comparing the added value to the value of the second NCO table(42). The phase is corrected by applying the cosine and the sine values to a received signal.