| 摘要 |
PURPOSE: A tracking device of a digital broadcasting receiver is provided to enable FFT window timing tracking continuously by detecting an index having the greatest power on the basis of output power of an equalizer part to extract FFT window timing information. CONSTITUTION: A tuner block(201) receives OFDM(Orthogonal Frequency Division Multiplex)-modulated bit stream of a base band signal for tuning a channel one wants and outputting as an intermediate frequency. An analog to digital converter(202) converts an analog signal output from the tuner block(201) into a digital signal. An I/Q generator(203) generates the digital signal output from the Analog to digital converter(202) as an I signal and a Q signal which are base band signals. A frequency compensator(204) compensates I and Q domains of the digital signal by AFC(Automatic Frequency Control). A FFT(Fast Fourier Transform) processor(205) transforms data components output through the frequency compensator(204) into frequency. An equalizer(206) calculates channel response in all frequency index by interpolating frequency-transformed data in time direction and then interpolating the same in frequency direction, and performs equalization by dividing input frequency data. A FFT window timing tracking part(210) calculates power of each channel response by output of time interpolation of the equalizer(206) and outputs index value having the greatest power. A timing synchronizer(211) applies with timing synchronization of I and Q domains input from the frequency compensator(204) to the FFT processor according to the index value input from the FFT window timing tracking part(210).
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