Method for determining a reference pulse phase from band-limited digital data streams

Abstract

The invention provides a method for recovering a digital datastream (301), in which a reference clock phase (308) is recovered from the digital datastream (301), the digital datastream (301) being received in a datastream receiver (302), low-pass filtered in a low-pass filter device (303), an edge position signal (309) being determined by comparing an amplitude of the low-pass filtered datastream (305) with a predeterminable threshold value (108) in an edge position detection device (304) and a phase deviation (111a) being determined from a time difference between a 0 / 1 threshold intersection point (109) of the threshold value (108) with a 0 / 1 data transition (101) or a -1 / 1 threshold intersection point (110) of the threshold value (108) with a -1 / 1 data transmission (102) and the target time of the control system (310) in a phase correction device (307), so that the phase deviation (111a) can be corrected with the phase correction offset (111b) in the phase correction device (307).

Description

Technical field [0001] The present invention relates to a method of recovering a digital data stream, and more specifically, the present invention relates to a method of recovering a reference clock phase from a digital data stream. Background technique [0002] For example, the data stream is transmitted as an AMI (Signal Alternate Inversion) data stream. In the AMI data transmission method, the two lines do not have a DC (direct current) component in order to transmit the data stream, and the analog signal on one line is reversed with respect to the analog signal on the other line. [0003] In the following, a logic signal is a signal whose signal level changes from one logic state to another logic state, and it can be assumed that these signals have a minimum data flow value, a baseline value, or a maximum data flow value. In this structure, the smallest data flow value is called logic "-1", the baseline value is called logic "0", and the largest data flow value is logic "+1"....

AI Technical Summary

Problems solved by technology

[0009] The disadvantage of this conventional approach is that bit-pattern-dependent distortions must be avoided, and as a result, the spectrum of the data stream must also contain frequency components above the central frequency of the useful signal

[0010] This creates additional disadvantages: noise components are also transmitted and amplified, which degrades the effective signal and increases phase jitter

[0012] Furthermore, disturbances such as jitter, i.e. common noise, band limitation due to the transmission channel, etc. have an adverse effect on the determination of the reference clock phase RT, therefore, there is a large error in such conventional determination methods

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