Abstract

Blind equalization and carrier phase recovery in a simulated 14 Gbaud 16-QAM optical coherent system are investigated. Equalization techniques to compensate for linear transmission impairments are presented using the constant modulus algorithm (CMA), the recursive least-squares (RLS)-CMA, and the radius directed equalization (RDE). With 7 T/2-spaced taps, the RDE and the RLS-CMA can compensate up to 1000 ps/nm of CD in the 16-QAM coherent system with performances comparable to the decision-directed (DD) equalizer. We show that the RDE is a promising technique for blind equalization in a 16-QAM coherent system with lower complexity than the RLS-CMA. Blind carrier phase recovery is investigated in a decision-directed-mode. We show that the blind carrier phase recovery algorithm can recover the Square-16-QAM constellation for laser beat linewidths of $\Delta \nu T_{s} \sim 10^{-4}$ in a polarization-multiplexed (POLMUX) 16-QAM coherent system with the RDE algorithm giving better overall performance than the CMA when compensating for CD and differential group delay (DGD). Finally, the dynamical characteristics of the equalizers to track endless polarization rotations are discussed. With the adaptation parameters optimized, the equalizers can track angular rate of rotation ${\sim 10}^{5}~$ rad/s.

© 2009 IEEE

PDF Article

References

  • View by:
  • |
  • |

  1. S. Walklin, J. Conradi, "Multilevel signaling for increasing the reach of 10 Gb/s lightwave systems," J. Lightw. Technol. 17, 2235-2248 (1999).
  2. J. Kahn, K.-P. Ho, "Spectral efficiency limits and modulation/detection techniques for DWDM systems," IEEE J. Sel. Topics Quant. Electron. 10, 259-272 (2004).
  3. N. Kikuchi, K. Sekine, S. Sasaki, Multilevel Signalling for High-Speed Optical Transmission, (2006) paper Tu3.2.1.
  4. N. Kikuchi, "Intersymbol interference (ISI) suppression technique for optical binary and multilevel signal generation," J. Lightw. Technol. 25, 2060-2068 (2007).
  5. E. Ip, J. M. Kahn, "Digital equalization of chromatic dispersion and polarization mode dispersion," J. Lightw. Technol. 25, 2033-2043 (2007).
  6. Y. Sato, "A method of self-recovering equalization for multilevel amplitude-modulation systems," IEEE Trans. Commun. COM-23, 679-682 (1975).
  7. C. R. Johnson, P. Schniter, T. J. Endres, J. D. Behm, D. R. Brown, R. A. Casas, "Blind equalization using the constant modulus criterion: A review," Proc. IEEE 86, 1927-1950 (1998).
  8. M. J. Ready, R. P. Gooch, "Blind equalization based on radius directed adaptation," Proc. ICASSP (1990) pp. 1699-1702.
  9. H. Louchet, K. Kuzmin, A. Richter, "Improved DSP algorithms for coherent 16-QAM transmission," ECOC 2008 BrusselsBelgium (2008) paper Tu.1.E.6.
  10. M. Seimetz, "Laser linewidth limitations for optical systems with high-order modulation employing feed forward digital carrier phase estimation," OFC/NFOEC (2008) paper OTuM2.
  11. M. Seimetz, "Performance of coherent optical square-16-QAM-systems based on IQ-transmitters and homodyne receivers with digital phase estimation," Nat. Fiber Optic Engineers Conf. AnaheimCA (2006) paper NWA4.
  12. E. Ip, J. M. Kahn, "Feedforward carrier recovery for coherent optical communications," J. Lightw. Technol. 25, 2675-2692 (2007).
  13. D. Godard, "Self-recovering equalization and carrier tracking in two-dimensional data communication systems," IEEE Trans. Commun. 28, 1867-1875 (1980).
  14. J. R. Treichler, B. G. Agee, "A new approach to multipath correction of constant modulus signals," IEEE Trans. Acoust., Speech, Signal Process. ASSP-31, 459-472 (1983).
  15. J. G. Proakis, Digital Communications (McGraw-Hill, 2001).
  16. Y. Chen, T. Le-Ngoc, B. Champagne, X. Changjiang, "Recursive least squares constant modulus algorithm for blind adaptive array," IEEE Trans. Signal Process. 52, 1452-1456 (2004).
  17. O. Macchi, E. Eweda, "Convergence analysis of self-adaptive equalizers," IEEE Trans. Inf. Theory 30, 161-176 (1984).
  18. G. Picchi, G. Prati, "Stop-and-go decision-directed algorithm," IEEE Trans. Commun. 35, 877-887 (1987).
  19. P. J. Winzer, A. H. Gnauck, "112-Gb/s polarization-multiplexed 16-QAM on a 25-GHz WDM grid," ECOC BrusselsBelgium (2008) paper Th.3.E.5.
  20. S. J. Savory, "Digital filters for coherent optical receivers," Opt. Exp. 16, 804-817 (2008).

2008 (1)

S. J. Savory, "Digital filters for coherent optical receivers," Opt. Exp. 16, 804-817 (2008).

2007 (3)

N. Kikuchi, "Intersymbol interference (ISI) suppression technique for optical binary and multilevel signal generation," J. Lightw. Technol. 25, 2060-2068 (2007).

E. Ip, J. M. Kahn, "Digital equalization of chromatic dispersion and polarization mode dispersion," J. Lightw. Technol. 25, 2033-2043 (2007).

E. Ip, J. M. Kahn, "Feedforward carrier recovery for coherent optical communications," J. Lightw. Technol. 25, 2675-2692 (2007).

2004 (2)

J. Kahn, K.-P. Ho, "Spectral efficiency limits and modulation/detection techniques for DWDM systems," IEEE J. Sel. Topics Quant. Electron. 10, 259-272 (2004).

Y. Chen, T. Le-Ngoc, B. Champagne, X. Changjiang, "Recursive least squares constant modulus algorithm for blind adaptive array," IEEE Trans. Signal Process. 52, 1452-1456 (2004).

1999 (1)

S. Walklin, J. Conradi, "Multilevel signaling for increasing the reach of 10 Gb/s lightwave systems," J. Lightw. Technol. 17, 2235-2248 (1999).

1998 (1)

C. R. Johnson, P. Schniter, T. J. Endres, J. D. Behm, D. R. Brown, R. A. Casas, "Blind equalization using the constant modulus criterion: A review," Proc. IEEE 86, 1927-1950 (1998).

1987 (1)

G. Picchi, G. Prati, "Stop-and-go decision-directed algorithm," IEEE Trans. Commun. 35, 877-887 (1987).

1984 (1)

O. Macchi, E. Eweda, "Convergence analysis of self-adaptive equalizers," IEEE Trans. Inf. Theory 30, 161-176 (1984).

1983 (1)

J. R. Treichler, B. G. Agee, "A new approach to multipath correction of constant modulus signals," IEEE Trans. Acoust., Speech, Signal Process. ASSP-31, 459-472 (1983).

1980 (1)

D. Godard, "Self-recovering equalization and carrier tracking in two-dimensional data communication systems," IEEE Trans. Commun. 28, 1867-1875 (1980).

1975 (1)

Y. Sato, "A method of self-recovering equalization for multilevel amplitude-modulation systems," IEEE Trans. Commun. COM-23, 679-682 (1975).

IEEE J. Sel. Topics Quant. Electron. (1)

J. Kahn, K.-P. Ho, "Spectral efficiency limits and modulation/detection techniques for DWDM systems," IEEE J. Sel. Topics Quant. Electron. 10, 259-272 (2004).

IEEE Trans. Acoust., Speech, Signal Process. (1)

J. R. Treichler, B. G. Agee, "A new approach to multipath correction of constant modulus signals," IEEE Trans. Acoust., Speech, Signal Process. ASSP-31, 459-472 (1983).

IEEE Trans. Commun. (3)

D. Godard, "Self-recovering equalization and carrier tracking in two-dimensional data communication systems," IEEE Trans. Commun. 28, 1867-1875 (1980).

G. Picchi, G. Prati, "Stop-and-go decision-directed algorithm," IEEE Trans. Commun. 35, 877-887 (1987).

Y. Sato, "A method of self-recovering equalization for multilevel amplitude-modulation systems," IEEE Trans. Commun. COM-23, 679-682 (1975).

IEEE Trans. Inf. Theory (1)

O. Macchi, E. Eweda, "Convergence analysis of self-adaptive equalizers," IEEE Trans. Inf. Theory 30, 161-176 (1984).

IEEE Trans. Signal Process. (1)

Y. Chen, T. Le-Ngoc, B. Champagne, X. Changjiang, "Recursive least squares constant modulus algorithm for blind adaptive array," IEEE Trans. Signal Process. 52, 1452-1456 (2004).

J. Lightw. Technol. (4)

S. Walklin, J. Conradi, "Multilevel signaling for increasing the reach of 10 Gb/s lightwave systems," J. Lightw. Technol. 17, 2235-2248 (1999).

E. Ip, J. M. Kahn, "Feedforward carrier recovery for coherent optical communications," J. Lightw. Technol. 25, 2675-2692 (2007).

N. Kikuchi, "Intersymbol interference (ISI) suppression technique for optical binary and multilevel signal generation," J. Lightw. Technol. 25, 2060-2068 (2007).

E. Ip, J. M. Kahn, "Digital equalization of chromatic dispersion and polarization mode dispersion," J. Lightw. Technol. 25, 2033-2043 (2007).

Opt. Exp. (1)

S. J. Savory, "Digital filters for coherent optical receivers," Opt. Exp. 16, 804-817 (2008).

Proc. IEEE (1)

C. R. Johnson, P. Schniter, T. J. Endres, J. D. Behm, D. R. Brown, R. A. Casas, "Blind equalization using the constant modulus criterion: A review," Proc. IEEE 86, 1927-1950 (1998).

Other (7)

M. J. Ready, R. P. Gooch, "Blind equalization based on radius directed adaptation," Proc. ICASSP (1990) pp. 1699-1702.

H. Louchet, K. Kuzmin, A. Richter, "Improved DSP algorithms for coherent 16-QAM transmission," ECOC 2008 BrusselsBelgium (2008) paper Tu.1.E.6.

M. Seimetz, "Laser linewidth limitations for optical systems with high-order modulation employing feed forward digital carrier phase estimation," OFC/NFOEC (2008) paper OTuM2.

M. Seimetz, "Performance of coherent optical square-16-QAM-systems based on IQ-transmitters and homodyne receivers with digital phase estimation," Nat. Fiber Optic Engineers Conf. AnaheimCA (2006) paper NWA4.

N. Kikuchi, K. Sekine, S. Sasaki, Multilevel Signalling for High-Speed Optical Transmission, (2006) paper Tu3.2.1.

J. G. Proakis, Digital Communications (McGraw-Hill, 2001).

P. J. Winzer, A. H. Gnauck, "112-Gb/s polarization-multiplexed 16-QAM on a 25-GHz WDM grid," ECOC BrusselsBelgium (2008) paper Th.3.E.5.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.