Abstract

Optical orthogonal frequency-division multiplexing (OOFDM) signal is sensitive to nonlinear distortions induced by optical modulators. We propose and experimentally demonstrate a digital pre-distortion (DPD) algorithm to linearize the optical modulators including electro-absorption modulated lasers (EML) and Mach-Zehnder modulators (MZM) used in high-speed OOFDM transmitters. By using an adaptive DPD algorithm with a learning structure, the inverse transfer function of a modulator, which is based on a polynomial model, has been obtained. In the experiment, the performance improvements with and without considering the memory effects of the DPD model are illustrated. The two typical kinds of high-speed OOFDM signals with a bit rate up to 30-Gb/s have been implemented experimentally. The results show that the nonlinear distortion induced by optical modulators can be compensated by using the DPD algorithm to substantially improve the optical modulation index.

© 2013 OSA

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. D. Z. Hsu, C. C. Wei, H. Y. Chen, J. Chen, M. C. Yuang, S. H. Lin, and W. Y. Li, “21 Gb/s after 100 km OFDM long-reach PON transmission using a cost-effective electro-absorption modulator,” Opt. Express18(26), 27758–27763 (2010).
    [CrossRef] [PubMed]
  2. W. R. Peng, I. Morita, H. Takahashi, and T. Tsuritani, “Transmission of high-speed (>100-Gb/s) direct-detection optical OFDM superchannel,” J. Lightwave Technol.30(12), 2025–2034 (2012).
    [CrossRef]
  3. Y. T. Moon, J. W. Jang, W. K. Choi, and Y. W. Choi, “Simultaneous noise and distortion reduction of a broadband optical feedforward transmitter for multi-service operation in radio-over-fiber systems,” Opt. Express15(19), 12167–12173 (2007).
    [CrossRef] [PubMed]
  4. Y. Shen, B. Hraimel, X. Zhang, G. E. R. Cowan, K. Wu, and T. Liu, “A novel analog broadband RF predistortion circuit to linearize electro-absorption modulators in multiband OFDM radio-over-fiber systems,” IEEE Trans. Microw. Theory Tech.58(11), 3327–3335 (2010).
    [CrossRef]
  5. B. Hraimel and X. Zhang, “A low cost broadband predistortion linearized single drive x-cut Mach-Zehnder modulator for radio-over-fiber systems,” IEEE Photon. Technol. Lett.24(18), 1571–1573 (2012).
    [CrossRef]
  6. D. R. Morgan, Z. Ma, J. Kim, M. G. Zierdt, and J. Pastalan, “A generalized memory polynomial model for digital predistortion of RF power amplifiers,” IEEE Trans. Signal Process.54(10), 3852–3860 (2006).
    [CrossRef]
  7. L. Ding, G. T. Zhou, D. R. Morgan, Z. Ma, J. S. Kenney, J. Kim, and C. R. Giardina, “A robust digital baseband predistorter constructed using memory polynomials,” IEEE Trans. Commun.52(1), 159–165 (2004).
    [CrossRef]
  8. D. J. F. Barros and J. M. Kahn, “Optical modulator optimization for orthogonal frequency-division multiplexing,” J. Lightwave Technol.27(13), 2370–2378 (2009).
    [CrossRef]
  9. Z. Liu, M. A. Violas, and N. B. Carvalho, “Digital predistortion for RSOAs as external modulators in radio over fiber systems,” Opt. Express19(18), 17641–17646 (2011).
    [CrossRef] [PubMed]
  10. T. Alves, J. Morgado, and A. Cartaxo, “Linearity improvement of directly modulated PONs by digital pre-distortion of coexisting OFDM-based signals,” in Proceedings of Advanced Photonics Congress, (Optical Society of America, 2012), paper AW4A.2.

2012

W. R. Peng, I. Morita, H. Takahashi, and T. Tsuritani, “Transmission of high-speed (>100-Gb/s) direct-detection optical OFDM superchannel,” J. Lightwave Technol.30(12), 2025–2034 (2012).
[CrossRef]

B. Hraimel and X. Zhang, “A low cost broadband predistortion linearized single drive x-cut Mach-Zehnder modulator for radio-over-fiber systems,” IEEE Photon. Technol. Lett.24(18), 1571–1573 (2012).
[CrossRef]

2011

2010

D. Z. Hsu, C. C. Wei, H. Y. Chen, J. Chen, M. C. Yuang, S. H. Lin, and W. Y. Li, “21 Gb/s after 100 km OFDM long-reach PON transmission using a cost-effective electro-absorption modulator,” Opt. Express18(26), 27758–27763 (2010).
[CrossRef] [PubMed]

Y. Shen, B. Hraimel, X. Zhang, G. E. R. Cowan, K. Wu, and T. Liu, “A novel analog broadband RF predistortion circuit to linearize electro-absorption modulators in multiband OFDM radio-over-fiber systems,” IEEE Trans. Microw. Theory Tech.58(11), 3327–3335 (2010).
[CrossRef]

2009

2007

2006

D. R. Morgan, Z. Ma, J. Kim, M. G. Zierdt, and J. Pastalan, “A generalized memory polynomial model for digital predistortion of RF power amplifiers,” IEEE Trans. Signal Process.54(10), 3852–3860 (2006).
[CrossRef]

2004

L. Ding, G. T. Zhou, D. R. Morgan, Z. Ma, J. S. Kenney, J. Kim, and C. R. Giardina, “A robust digital baseband predistorter constructed using memory polynomials,” IEEE Trans. Commun.52(1), 159–165 (2004).
[CrossRef]

Barros, D. J. F.

Carvalho, N. B.

Chen, H. Y.

Chen, J.

Choi, W. K.

Choi, Y. W.

Cowan, G. E. R.

Y. Shen, B. Hraimel, X. Zhang, G. E. R. Cowan, K. Wu, and T. Liu, “A novel analog broadband RF predistortion circuit to linearize electro-absorption modulators in multiband OFDM radio-over-fiber systems,” IEEE Trans. Microw. Theory Tech.58(11), 3327–3335 (2010).
[CrossRef]

Ding, L.

L. Ding, G. T. Zhou, D. R. Morgan, Z. Ma, J. S. Kenney, J. Kim, and C. R. Giardina, “A robust digital baseband predistorter constructed using memory polynomials,” IEEE Trans. Commun.52(1), 159–165 (2004).
[CrossRef]

Giardina, C. R.

L. Ding, G. T. Zhou, D. R. Morgan, Z. Ma, J. S. Kenney, J. Kim, and C. R. Giardina, “A robust digital baseband predistorter constructed using memory polynomials,” IEEE Trans. Commun.52(1), 159–165 (2004).
[CrossRef]

Hraimel, B.

B. Hraimel and X. Zhang, “A low cost broadband predistortion linearized single drive x-cut Mach-Zehnder modulator for radio-over-fiber systems,” IEEE Photon. Technol. Lett.24(18), 1571–1573 (2012).
[CrossRef]

Y. Shen, B. Hraimel, X. Zhang, G. E. R. Cowan, K. Wu, and T. Liu, “A novel analog broadband RF predistortion circuit to linearize electro-absorption modulators in multiband OFDM radio-over-fiber systems,” IEEE Trans. Microw. Theory Tech.58(11), 3327–3335 (2010).
[CrossRef]

Hsu, D. Z.

Jang, J. W.

Kahn, J. M.

Kenney, J. S.

L. Ding, G. T. Zhou, D. R. Morgan, Z. Ma, J. S. Kenney, J. Kim, and C. R. Giardina, “A robust digital baseband predistorter constructed using memory polynomials,” IEEE Trans. Commun.52(1), 159–165 (2004).
[CrossRef]

Kim, J.

D. R. Morgan, Z. Ma, J. Kim, M. G. Zierdt, and J. Pastalan, “A generalized memory polynomial model for digital predistortion of RF power amplifiers,” IEEE Trans. Signal Process.54(10), 3852–3860 (2006).
[CrossRef]

L. Ding, G. T. Zhou, D. R. Morgan, Z. Ma, J. S. Kenney, J. Kim, and C. R. Giardina, “A robust digital baseband predistorter constructed using memory polynomials,” IEEE Trans. Commun.52(1), 159–165 (2004).
[CrossRef]

Li, W. Y.

Lin, S. H.

Liu, T.

Y. Shen, B. Hraimel, X. Zhang, G. E. R. Cowan, K. Wu, and T. Liu, “A novel analog broadband RF predistortion circuit to linearize electro-absorption modulators in multiband OFDM radio-over-fiber systems,” IEEE Trans. Microw. Theory Tech.58(11), 3327–3335 (2010).
[CrossRef]

Liu, Z.

Ma, Z.

D. R. Morgan, Z. Ma, J. Kim, M. G. Zierdt, and J. Pastalan, “A generalized memory polynomial model for digital predistortion of RF power amplifiers,” IEEE Trans. Signal Process.54(10), 3852–3860 (2006).
[CrossRef]

L. Ding, G. T. Zhou, D. R. Morgan, Z. Ma, J. S. Kenney, J. Kim, and C. R. Giardina, “A robust digital baseband predistorter constructed using memory polynomials,” IEEE Trans. Commun.52(1), 159–165 (2004).
[CrossRef]

Moon, Y. T.

Morgan, D. R.

D. R. Morgan, Z. Ma, J. Kim, M. G. Zierdt, and J. Pastalan, “A generalized memory polynomial model for digital predistortion of RF power amplifiers,” IEEE Trans. Signal Process.54(10), 3852–3860 (2006).
[CrossRef]

L. Ding, G. T. Zhou, D. R. Morgan, Z. Ma, J. S. Kenney, J. Kim, and C. R. Giardina, “A robust digital baseband predistorter constructed using memory polynomials,” IEEE Trans. Commun.52(1), 159–165 (2004).
[CrossRef]

Morita, I.

Pastalan, J.

D. R. Morgan, Z. Ma, J. Kim, M. G. Zierdt, and J. Pastalan, “A generalized memory polynomial model for digital predistortion of RF power amplifiers,” IEEE Trans. Signal Process.54(10), 3852–3860 (2006).
[CrossRef]

Peng, W. R.

Shen, Y.

Y. Shen, B. Hraimel, X. Zhang, G. E. R. Cowan, K. Wu, and T. Liu, “A novel analog broadband RF predistortion circuit to linearize electro-absorption modulators in multiband OFDM radio-over-fiber systems,” IEEE Trans. Microw. Theory Tech.58(11), 3327–3335 (2010).
[CrossRef]

Takahashi, H.

Tsuritani, T.

Violas, M. A.

Wei, C. C.

Wu, K.

Y. Shen, B. Hraimel, X. Zhang, G. E. R. Cowan, K. Wu, and T. Liu, “A novel analog broadband RF predistortion circuit to linearize electro-absorption modulators in multiband OFDM radio-over-fiber systems,” IEEE Trans. Microw. Theory Tech.58(11), 3327–3335 (2010).
[CrossRef]

Yuang, M. C.

Zhang, X.

B. Hraimel and X. Zhang, “A low cost broadband predistortion linearized single drive x-cut Mach-Zehnder modulator for radio-over-fiber systems,” IEEE Photon. Technol. Lett.24(18), 1571–1573 (2012).
[CrossRef]

Y. Shen, B. Hraimel, X. Zhang, G. E. R. Cowan, K. Wu, and T. Liu, “A novel analog broadband RF predistortion circuit to linearize electro-absorption modulators in multiband OFDM radio-over-fiber systems,” IEEE Trans. Microw. Theory Tech.58(11), 3327–3335 (2010).
[CrossRef]

Zhou, G. T.

L. Ding, G. T. Zhou, D. R. Morgan, Z. Ma, J. S. Kenney, J. Kim, and C. R. Giardina, “A robust digital baseband predistorter constructed using memory polynomials,” IEEE Trans. Commun.52(1), 159–165 (2004).
[CrossRef]

Zierdt, M. G.

D. R. Morgan, Z. Ma, J. Kim, M. G. Zierdt, and J. Pastalan, “A generalized memory polynomial model for digital predistortion of RF power amplifiers,” IEEE Trans. Signal Process.54(10), 3852–3860 (2006).
[CrossRef]

IEEE Photon. Technol. Lett.

B. Hraimel and X. Zhang, “A low cost broadband predistortion linearized single drive x-cut Mach-Zehnder modulator for radio-over-fiber systems,” IEEE Photon. Technol. Lett.24(18), 1571–1573 (2012).
[CrossRef]

IEEE Trans. Commun.

L. Ding, G. T. Zhou, D. R. Morgan, Z. Ma, J. S. Kenney, J. Kim, and C. R. Giardina, “A robust digital baseband predistorter constructed using memory polynomials,” IEEE Trans. Commun.52(1), 159–165 (2004).
[CrossRef]

IEEE Trans. Microw. Theory Tech.

Y. Shen, B. Hraimel, X. Zhang, G. E. R. Cowan, K. Wu, and T. Liu, “A novel analog broadband RF predistortion circuit to linearize electro-absorption modulators in multiband OFDM radio-over-fiber systems,” IEEE Trans. Microw. Theory Tech.58(11), 3327–3335 (2010).
[CrossRef]

IEEE Trans. Signal Process.

D. R. Morgan, Z. Ma, J. Kim, M. G. Zierdt, and J. Pastalan, “A generalized memory polynomial model for digital predistortion of RF power amplifiers,” IEEE Trans. Signal Process.54(10), 3852–3860 (2006).
[CrossRef]

J. Lightwave Technol.

Opt. Express

Other

T. Alves, J. Morgado, and A. Cartaxo, “Linearity improvement of directly modulated PONs by digital pre-distortion of coexisting OFDM-based signals,” in Proceedings of Advanced Photonics Congress, (Optical Society of America, 2012), paper AW4A.2.

Cited By

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

Alert me when this article is cited.


Figures (8)

Fig. 1
Fig. 1

The structure of the OOFDM transmitter with DPD algorithm (dashed line).

Fig. 2
Fig. 2

The diagram of polynomial-based DPD block with memory effect.

Fig. 3
Fig. 3

Experimental setup of OOFDM transmitters with DPD algorithm. The EML and MZM are used to generate 30Gb/s CVOFDM signal and 20Gb/s RVOFDM signal, respectively.

Fig. 4
Fig. 4

Measured EVM results from the 30Gb/s CVOFDM system. (a) Transmitted EVM after iterations with different values of μ. (b) EVM of transmitted signal with memory or memoryless DPD algorithm. (c) EVM of transmitted signal with and without memory DPD algorithm.

Fig. 5
Fig. 5

AM/AM (a)(b) and AM/PM (c)(d) plots for received CVOFDM signal @OMI = 35% with and without memory DPD algorithm.

Fig. 6
Fig. 6

Power spectral density and constellations of received CVOFDM signal @OMI = 35% with and without memory DPD algorithm. (a), (b) and (c) are 16QAM, 32QAM and 64QAM CVOFDM signals, respectively.

Fig. 7
Fig. 7

(a) Linear region, DPD effective region and forbidden region of intensity modulation with MZM modulator. (b) Measured EVM results in the three regions with and without DPD algorithm.

Fig. 8
Fig. 8

Nonlinear distortion as peak clipping and memory effect induced by MZM modulator.

Equations (4)

Equations on this page are rendered with MathJax. Learn more.

x ˜ (n)=g( u ˜ (n)) = m M sml k K sml u ˜ (nm)| u ˜ (nm) | k w mk single memory layer + m M cml k K cml l L cml u ˜ (nm)| u ˜ (nml) | k w mkl cross memory layer = [ u ˜ (n) ] polynomial w.
w= ( U ˜ polynomial H U ˜ polynomial ) 1 U ˜ polynomial H X.
w p+1 = w p +μ ( U ˜ polynomial H U ˜ polynomial ) 1 U ˜ polynomial H E.
X= U polynomial w.

Metrics