In a clock recovery circuit for DTV using a VSB modulation method, if the frequency
of the symbol clock is fs, since the frequency difference between the fs/2 component
signal of the VSB signal and the pilot signal is constant at fs/2, it is possible
accurately to detect the phase error from their differential signal. Furthermore
there is no distortion of the clock signal frequency of the VSB signal, even when
the symbol data is distorted by multi-pass distortion or the like, since clock
signal regeneration is performed by frequency domain processing. By employing this
type of principle and performing phase error detection for each symbol at a time,
it is possible to ensure a high speed tracking performance for clock signal regeneration.
