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.
