Patent ID: 7194045

Claim:
A method for recovering a digital datastream in which a reference clock phase is recovered from the digital datastream, comprising: receiving the digital datastream in a datastream receiver; low-pass filtering the received digital datastream in a low-pass filter device; setting a threshold value in a threshold setting device; determining an edge position signal by comparing an amplitude of the low-pass-filtered datastream with the threshold value in an edge position detection device; determining a phase correction value from a time difference between a 0/1 threshold intersection point of the threshold value with a 0/1 data transition and a −1/1 threshold intersection point of the threshold value with a −1/1 data transition in a phase correction device; correcting the edge position signal with the phase correction value in the phase correction device; and outputting a reference clock phase signal from the phase correction device, wherein determining and correcting further comprise: determining an edge slope of the data transitions in the phase correction device; and correlating the data transitions with the edge slope, and in each case a preceding data transition is provided for determining the edge position signal of a current data transition and the edge position signal is corrected with the phase correction value in the phase correction device, the phase correction value is calculated from a phase deviation and a phase correction offset if a preceding data transition and a current data transition differ, and the phase deviation of the preceding data transition is used as the phase correction value if the preceding data transition and the current data transition match.