Frequency deviation compensation scheme and frequency deviation compensation method
AssigneeNEC Corporation
InventorsDaisaku Ogasahara, Junichi Abe
Life of this patent
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Abstract
When a frequency deviation compensation amount is compensated for by use of frequency shift, a phase offset occurs between adjacent input blocks included in a plurality of input blocks as divided, with the result that an error occurs in a reconstructed bit sequence. A frequency deviation compensation system of the invention is characterized by comprising: a frequency deviation compensation means for compensating for a frequency deviation occurring in a signal by use of frequency shift; and a phase offset compensation means for compensating for a phase offset occurring, in the signal, due to the frequency shift.
Claims13
An optical communication system comprising:
- an optical transmitter configured to modulate a phase of an optical carrier using a digital signal that indicates a data series and is input to the optical transmitter as an electric signal, perform polarization multiplexing to phase-modulated optical signals to generate an optical signal, and output the optical signal;
- and
- an optical receiver configured to receive the optical signal, separate the received optical signal into single-polarization optical signals and to recover the digital signal,
- wherein the optical receiver includes:
- a frequency deviation compensator configured to compensate for a frequency deviation of the received optical signal by frequency shift process to a digital signal corresponding to the received optical signal;
- and
- a phase offset compensator configured to compensate for a phase offset of the frequency deviation-compensated digital signal caused by the frequency shift process.
An optical communication system comprising:
- an optical transmitter configured to modulate a phase of an optical carrier using a digital signal that indicates a data series and is input to the optical transmitter as an electric signal, perform polarization multiplexing to phase-modulated optical signals to generate an optical signal, and output the optical signal;
- and
- an optical receiver configured to receive the optical signal, separate the received optical signal into single-polarization optical signals and to recover the digital signal,
- wherein the optical receiver includes:
- a compensation amount calculator configured to identify a frequency deviation compensation amount corresponding to a predetermined phase offset amount of a digital signal corresponding to the received optical signal;
- and
- a frequency deviation compensator configured to compensate, based on the frequency deviation compensation amount, for a frequency deviation of the received optical signal by frequency shift process to the digital signal corresponding to the received optical signal.
Dependencies are inferred from the claim text.