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US 7,116,454 B2Granted
Method for determining signal quality in optical transmission systems
AssigneeSiemens Aktiengesellschaft
InventorsJoerg Peter Elbers, Christoph Glingener, Andreas Faerbert, Christian Scheerer
Life of this patent
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Abstract
A method for determining signal quality in optical transmission systems, wherein the effective signal-to-noise ratio is determined by measuring amplitude histograms of a signal and by calculating characteristic histogram moments and additional interference is ascertained by comparing the characteristic histogram moments with the optical signal-to-noise ratio.
Claims10
A method for determining signal quality in optical transmission systems by measuring an amplitude histogram of a signal, the method comprising the steps of:
- calculating characteristic histogram moments from the measured amplitude histogram;
- measuring directly an optical signal-to noise ratio from the signal;
- comparing the characteristic histogram moments with the measured optical signal-to-noise ratio;
- and
- determining, a proportion of non-linear noise if the comparison yields non-correspondence, wherein a relationship between the characteristic histogram moments and signal-to-noise ratio is determined using the following:
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- where μ0 and μ1 are average values of the amplitude distribution of the logic “1's” and “0's”, σ0 and σ1 are standard deviations of the amplitude distribution of the logic “1's” and “0's”, OSNR is signal-to-noise ratio, <P>av is an average signal power,
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- is an optical bandwidth, Bel is an electrical bandwidth of a photodiode or an opto-electrical transducer, and =ηq/hv is detector sensitivity (η=quantum efficiency, q=elementary charge, h=quantum of action, v=frequency of the signal).
164 more elements
Dependencies are inferred from the claim text.