Abstract

We report an adaptive weighted channel equalizer (AWCE) for orthogonal frequency division multiplexing (OFDM) and study its performance for long-haul coherent optical OFDM (CO-OFDM) transmission systems. This equalizer updates the equalization parameters on a symbol-by-symbol basis thus can track slight drifts of the optical channel. This is suitable to combat polarization mode dispersion (PMD) degradation while increasing the periodicity of pilot symbols which can be translated into a significant overhead reduction. Furthermore, AWCE can increase the precision of RF-pilot enabled phase noise estimation in the presence of noise, using data-aided phase noise estimation. Simulation results corroborate the capability of AWCE in both overhead reduction and improving the quality of the phase noise compensation (PNC).

© 2010 OSA

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References

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  1. W. Shieh, H. Bao, and Y. Tang, “Coherent optical OFDM: theory and design,” Opt. Express 16(2), 841–859 (2008).
    [CrossRef] [PubMed]
  2. W. Shieh, X. Yi, Y. Ma, and Q. Yang, “Coherent optical OFDM: has its time come?” J. Opt. Netw. 7(3), 234–255 (2008).
    [CrossRef]
  3. I. B. Djordjevic and B. Vasic, “Orthogonal frequency division multiplexing for high-speed optical transmission,” Opt. Express 14(9), 3767–3775 (2006).
    [CrossRef] [PubMed]
  4. S. L. Jansen, I. Morita, T. Schenk, N. Takeda, and H. Tankada, “Coherent Optical 25.8-Gb/s OFDM Transmission Over 4160-km SSMF,” J. Lightwave Technol. 26(1), 6–15 (2008).
    [CrossRef]
  5. S. L. Jansen, I. Morita, T. C. W. Schenk, N. Takeda, and H. Tanaka, “Theoretical and experimental investigations of direct-detected RF-tone assisted optical OFDM systems,” J. Lightwave Technol. 27(10), 1332–1339 (2009).
    [CrossRef]
  6. X. Liu and F. Buchali, “Intra-symbol frequency-domain averaging based channel estimation for coherent optical OFDM,” Opt. Express 16(26), 21944–21957 (2008).
    [CrossRef] [PubMed]
  7. M. Karlsson, J. Brentel, and P. A. Andrekson, “Long-term Measurement of PMD and Polarization Drift in Installed Fibers,” J. Lightwave Technol. 18(7), 941–951 (2000).
    [CrossRef]
  8. P. Krummrich, and K. Kotten, “Extremely fast (microsecond timescale) polarization changes in high speed long haul WDM transmission systems,” in Optical Fiber Communication Conference, OSA Technical Digest Series (CD) (Optical Society of America, 2004), paper FI3.
  9. F. Buchali, R. Dischler, and X. Liu, “Optical OFDM: A Promising High-Speed Optical Transport Technology,” Bell Labs Tech. J. 14(1), 125–148 (2009).
    [CrossRef]
  10. X. Yi, W. Shieh, and Y. Tang, “Phase Estimation for Coherent Optical OFDM,” IEEE Photon. Technol. Lett. 19(12), 919–921 (2007).
    [CrossRef]
  11. S. L. Jansen, I. Morita, N. Takeda, and H. Tanaka, “20-Gb/s OFDM transmission over 4,160-km SSMF enabled by RF-Pilot tone phase noise compensation,” in Optical Fiber Communication Conference, OSA Technical Digest Series (CD) (Optical Society of America, 2007), paper PDP15.
  12. M. Rim, “Optimally combining decision-directed and pilot-symbol-aided channel estimation,” Electron. Lett. 39(6), 558–560 (2003).
    [CrossRef]
  13. J. Ran, R. Grunheid, H. Rohling, E. Bolinth, and R. Kern, “Decision-directed channel estimation method for OFDM systems with high velocities,” in Proceedings of IEEE Vehicular Technology Conference, (Institute of Electrical and Electronics Engineers, New York, 2003), pp. 2358–2361.
  14. M. E. Mousa Pasandi, J. Haghighat, and D. V. Plant, “Adaptive weighted channel equalizer for direct-detection optical OFDM transmission systems,” in Proceedings of IEEE Photonics Society Summer Topicals’09, (Institute of Electrical and Electronics Engineers, New York, 2009), pp. 85–86.
  15. J. Palicot and A. Goupil, “Performance analysis of the weighted decision feedback equalizer,” Signal Process. 88(2), 284–295 (2008).
    [CrossRef]
  16. R. W. Tkach and A. R. Chraplyvy, “Phase Noise and Linewidth in an InGaAsP DFB Laser,” J. Lightwave Technol. 4(11), 1711–1716 (1986).
    [CrossRef]
  17. C. Xie, D. Werner, and H. F. Haunstein, “Dynamic Performance and Speed Requirement of Polarization Mode Dispersion Compensators,” J. Lightwave Technol. 24(11), 3968–3975 (2006).
    [CrossRef]

2009 (2)

2008 (5)

2007 (1)

X. Yi, W. Shieh, and Y. Tang, “Phase Estimation for Coherent Optical OFDM,” IEEE Photon. Technol. Lett. 19(12), 919–921 (2007).
[CrossRef]

2006 (2)

2003 (1)

M. Rim, “Optimally combining decision-directed and pilot-symbol-aided channel estimation,” Electron. Lett. 39(6), 558–560 (2003).
[CrossRef]

2000 (1)

1986 (1)

R. W. Tkach and A. R. Chraplyvy, “Phase Noise and Linewidth in an InGaAsP DFB Laser,” J. Lightwave Technol. 4(11), 1711–1716 (1986).
[CrossRef]

Andrekson, P. A.

Bao, H.

Brentel, J.

Buchali, F.

F. Buchali, R. Dischler, and X. Liu, “Optical OFDM: A Promising High-Speed Optical Transport Technology,” Bell Labs Tech. J. 14(1), 125–148 (2009).
[CrossRef]

X. Liu and F. Buchali, “Intra-symbol frequency-domain averaging based channel estimation for coherent optical OFDM,” Opt. Express 16(26), 21944–21957 (2008).
[CrossRef] [PubMed]

Chraplyvy, A. R.

R. W. Tkach and A. R. Chraplyvy, “Phase Noise and Linewidth in an InGaAsP DFB Laser,” J. Lightwave Technol. 4(11), 1711–1716 (1986).
[CrossRef]

Dischler, R.

F. Buchali, R. Dischler, and X. Liu, “Optical OFDM: A Promising High-Speed Optical Transport Technology,” Bell Labs Tech. J. 14(1), 125–148 (2009).
[CrossRef]

Djordjevic, I. B.

Goupil, A.

J. Palicot and A. Goupil, “Performance analysis of the weighted decision feedback equalizer,” Signal Process. 88(2), 284–295 (2008).
[CrossRef]

Haunstein, H. F.

Jansen, S. L.

Karlsson, M.

Liu, X.

F. Buchali, R. Dischler, and X. Liu, “Optical OFDM: A Promising High-Speed Optical Transport Technology,” Bell Labs Tech. J. 14(1), 125–148 (2009).
[CrossRef]

X. Liu and F. Buchali, “Intra-symbol frequency-domain averaging based channel estimation for coherent optical OFDM,” Opt. Express 16(26), 21944–21957 (2008).
[CrossRef] [PubMed]

Ma, Y.

Morita, I.

Palicot, J.

J. Palicot and A. Goupil, “Performance analysis of the weighted decision feedback equalizer,” Signal Process. 88(2), 284–295 (2008).
[CrossRef]

Rim, M.

M. Rim, “Optimally combining decision-directed and pilot-symbol-aided channel estimation,” Electron. Lett. 39(6), 558–560 (2003).
[CrossRef]

Schenk, T.

Schenk, T. C. W.

Shieh, W.

Takeda, N.

Tanaka, H.

Tang, Y.

W. Shieh, H. Bao, and Y. Tang, “Coherent optical OFDM: theory and design,” Opt. Express 16(2), 841–859 (2008).
[CrossRef] [PubMed]

X. Yi, W. Shieh, and Y. Tang, “Phase Estimation for Coherent Optical OFDM,” IEEE Photon. Technol. Lett. 19(12), 919–921 (2007).
[CrossRef]

Tankada, H.

Tkach, R. W.

R. W. Tkach and A. R. Chraplyvy, “Phase Noise and Linewidth in an InGaAsP DFB Laser,” J. Lightwave Technol. 4(11), 1711–1716 (1986).
[CrossRef]

Vasic, B.

Werner, D.

Xie, C.

Yang, Q.

Yi, X.

W. Shieh, X. Yi, Y. Ma, and Q. Yang, “Coherent optical OFDM: has its time come?” J. Opt. Netw. 7(3), 234–255 (2008).
[CrossRef]

X. Yi, W. Shieh, and Y. Tang, “Phase Estimation for Coherent Optical OFDM,” IEEE Photon. Technol. Lett. 19(12), 919–921 (2007).
[CrossRef]

Bell Labs Tech. J. (1)

F. Buchali, R. Dischler, and X. Liu, “Optical OFDM: A Promising High-Speed Optical Transport Technology,” Bell Labs Tech. J. 14(1), 125–148 (2009).
[CrossRef]

Electron. Lett. (1)

M. Rim, “Optimally combining decision-directed and pilot-symbol-aided channel estimation,” Electron. Lett. 39(6), 558–560 (2003).
[CrossRef]

IEEE Photon. Technol. Lett. (1)

X. Yi, W. Shieh, and Y. Tang, “Phase Estimation for Coherent Optical OFDM,” IEEE Photon. Technol. Lett. 19(12), 919–921 (2007).
[CrossRef]

J. Lightwave Technol. (5)

J. Opt. Netw. (1)

Opt. Express (3)

Signal Process. (1)

J. Palicot and A. Goupil, “Performance analysis of the weighted decision feedback equalizer,” Signal Process. 88(2), 284–295 (2008).
[CrossRef]

Other (4)

J. Ran, R. Grunheid, H. Rohling, E. Bolinth, and R. Kern, “Decision-directed channel estimation method for OFDM systems with high velocities,” in Proceedings of IEEE Vehicular Technology Conference, (Institute of Electrical and Electronics Engineers, New York, 2003), pp. 2358–2361.

M. E. Mousa Pasandi, J. Haghighat, and D. V. Plant, “Adaptive weighted channel equalizer for direct-detection optical OFDM transmission systems,” in Proceedings of IEEE Photonics Society Summer Topicals’09, (Institute of Electrical and Electronics Engineers, New York, 2009), pp. 85–86.

P. Krummrich, and K. Kotten, “Extremely fast (microsecond timescale) polarization changes in high speed long haul WDM transmission systems,” in Optical Fiber Communication Conference, OSA Technical Digest Series (CD) (Optical Society of America, 2004), paper FI3.

S. L. Jansen, I. Morita, N. Takeda, and H. Tanaka, “20-Gb/s OFDM transmission over 4,160-km SSMF enabled by RF-Pilot tone phase noise compensation,” in Optical Fiber Communication Conference, OSA Technical Digest Series (CD) (Optical Society of America, 2007), paper PDP15.

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Figures (6)

Fig. 1
Fig. 1

Error-vector of one equalized received constellation point (a). The scenarios of accurate (b) and inaccurate (c) equalization due to the drift. Blue points represent the ideal constellation points. Red points illustrate the constellation points of one received OFDM symbol after equalization.

Fig. 2
Fig. 2

Simulation setup.

Fig. 3
Fig. 3

OFDM spectrum with RF-pilot enabled phase noise compensation. PSR is the ratio between RF-pilot power and the power of all subcarriers.

Fig. 4
Fig. 4

The BER performance of the data-aided PNC for two different received OSNR values of 13 and 16 dB.

Fig. 5
Fig. 5

The comparison between the BER performance of ZFE with the PS overhead of 3% and 0.3% and AWCE with the PS overhead of 0.3%.

Fig. 6
Fig. 6

The comparison between the received constellations after 2000 km transmission, equalized by ZFE and AWCE. The PS overhead is 0.3% for both cases.

Equations (6)

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Δ O S N R P S ( d B ) = 10 × log [ ( m S Y M + m P S ) / m S Y M ]
S ^ n , k = R n , k H ˜ n 1 , k e j Δ ϕ p i l o t , n
H ^ n , k = R n , k S ¯ n , k
Δ ϕ A W C E , n = ( i = 1 N ( arg { H ^ n , i } arg { H ˜ n 1 , i } ) ) / N
H ˜ n , k = ( 1 γ ) H ^ n , k + γ H ˜ n 1 , k e j Δ ϕ A W C E , n
γ = 1 | a v g { r / d } |

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