System and method for multi-channel mitigation of PMD/PDL/PDG
AssigneeLucent Technologies Inc.
InventorsAdriaan J. de Lind van Wijngaarden, Xiang Liu, Chongjin Xie
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Abstract
A system and method for multi-channel PMD/PDL/PDG mitigation, the system including polarization scramblers adapted to vary the state of polarization of an optical signal propagated through the system to effectively vary the polarization mode dispersion experienced by the signal during each burst-error-correcting-period of the forward error correction used in the system.
Claims28
An optical transmission system employing forward error correction comprising:
- at least one polarization scrambler positioned along a transmission link;
- wherein the at least one polarization scrambler is adapted to vary the polarization state of an optical signal to vary the polarization mode dispersion experienced by the signal at least once during each burst-error-correcting-period of the forward error correction employed by the system;
- and
- wherein the speed of the at least one polarization scrambler is between about 0.5 BR/FEC-BECL and BR/N. where BR is the system bit rate, FEC-BECL is the forward error correction burst error correction length and N is the number of polarization scramblers.
A method for optical transmission in a multi-channel system employing forward error correction comprising,
- varying the polarization state of an optical signal to effectively vary the polarization mode dispersion experienced by the optical signal at least once during each burst-error-correction-period of the forward error correction employed by the system and
- wherein the polarization state is varied using one or more polarization scramblers having a speed of between about 0.5BR/FEC-BECL and about BR/N, where BR is the system bit rate. FEC-BECL is the forward error correction burst error correction length and N is the number of polarization scramblers.
An optical transmission system employing forward error correction comprising:
- at least one polarization scrambler positioned along a transmission link;
- wherein the at least one polarization scrambler is adapted to vary the polarization state of an optical signal to vary the polarization mode dispersion experienced by the signal at least once during each bursterror-correcting-period of the forward error correction employed by the system and the system employs a modulation formatting scheme selected from the group consisting of:
- on-off-keying modulation formatting;
- differential phase-shift keying modulation formatting;
- optical duobinary modulation formatting and differential quadrature-phase-shift-keying modulation formatting.
An apparatus for transmitting optical signals in a system employing forward error correction comprising,
- means for varying the state of polarization of the optical signals at least once during each burst-error-correction-period of the forward error correction code employed by the system;
- and
- wherein the polarization state varying means operates at a speed of between about 0.5BR/FEC-BECL and about BR/N, where BR is the system bit rate, FEC-BECL is the forward error correction burst error correction length and N is the number of polarization varying means.
An optical transmission system employing forward error correction comprising:
- at least one polarization scrambler including a multiple stage phase modulator wherein the multiple stages of the multiple-stage phase modulator are driven by sinusoidal drive signals having one or more different amplitudes and frequencies, said at least one polarization scrambler being positioned along a transmission link;
- wherein the at least one polarization scrambler is adapted to vary the polarization state of an optical signal to vary the polarization mode dispersion experienced by the signal at least once during each burst-error-correcting-period of the forward error correction employed by the system.
An optical transmission system employing forward error correction comprising:
- at least one polarization scrambler including a multiple stage fiber-based scrambler wherein the multiple stages of the fiber-based scrambler are driven by sinusoidal drive signals with different amplitudes and frequencies, said at least one polarization scrambler being positioned along a transmission link;
- wherein the at least one polarization scrambler is adapted to vary the polarization state of an optical signal to vary the polarization mode dispersion experienced by the signal at least once during each burst-error-correcting-period of the forward error correction employed by the system.
Dependencies are inferred from the claim text.