A read channel apparatus is disclosed for reading data recorded on an
optical storage system at a predetermined baud rate. The apparatus
asynchronously samples an analog read signal generating from the optical
storage system and subtracts an estimated DC offset from the asynchronous
sample values to generate a sequence of asynchronous DC-removed sample
values. The asynchronous DC-removed sample values are separately
interpolated by two interpolators to generate a sequence of synchronous
even-time sample values and a sequence of synchronous odd-time sample
values respectively. The synchronous even-time and odd-time sample values
are separately equalized by two equalizers in accordance with a target
spectrum to generate a sequence of even-time equalized sample values and
a sequence of odd-time equalized sample values respectively. A DC offset
estimator generates the estimated DC offset from the even-time equalized
sample values and the odd-time equalized sample values. The interpolators
are under the control of a timing recovery controller for synchronizing
the even-time and odd-time sample values to the baud rate. In the
preferred embodiment, the recorded data are determined from the even-time
equalized sample values and the odd-time equalized sample values.