Patent ID: 8160185

Claim:
An apparatus for synchronizing an OFDM signal using an open-loop frequency synchronization method, the apparatus comprising: an OFDM receiver comprising a low noise amplifier (LNA) amplifying a signal received from an antenna, a mixer converting the amplified signal into baseband signal using a clock frequency generated from a local oscillator, a band pass filter extracting and outputting a specific signal in the baseband signal, and an analog-to-digital converter (ADC) converting the extracted signal into a digital signal; a time offset estimator estimating a start position of an OFDM symbol and a start position of a frame with respect to the digital signal; a time offset compensator compensating for the start position of the OFDM symbol and the start point of the frame; a fractional frequency offset estimator estimating a frequency offset that becomes fraction times of an interval of a sub-carrier in response to a signal inputted from the time offset estimator; an integer frequency offset estimator estimating a frequency offset that becomes integer times of the interval of the sub-carrier in response to the signal inputted from the fractional frequency offset estimator; a frequency offset controller estimating a change in frequency offset that becomes integer times of the interval of the sub-carrier using the frequency offset that becomes fraction times of the interval of the sub-carrier; and a frequency offset compensator compensating the frequency offset using the start position of the OFDM symbol and the start point of the frame based on the estimated change in frequency offset.