Abstract

In this paper we propose a scheme for reducing the energy consumption of optical links by means of adaptive forward error correction (FEC). The scheme works by performing on the fly adjustments to the code rate of the FEC, adding extra parity bits to the data stream whenever extra capacity is available. We show that this additional parity information decreases the number of necessary decoding iterations and thus reduces the power consumption in iterative decoders during periods of low load. The code rate adjustments can be done on a frame-by-frame basis and thus make it possible to manipulate the balance between effective data rate and FEC coding gain without any disruption to the live traffic. As a consequence, these automatic adjustments can be performed very often based on the current traffic demand and bit error rate performance of the links through the network. The FEC scheme itself is designed to work as a transparent add-on to transceivers running the optical transport network (OTN) protocol, adding an extra layer of elastic soft-decision FEC to the built-in hard-decision FEC implemented in OTN, while retaining interoperability with existing OTN equipment. In order to facilitate dynamic code rate adaptation, we propose a programmable encoder and decoder design approach, which can implement various codes depending on the desired code rate using the same basic circuitry. This design ensures optimal coding gain performance with a modest overhead for supporting multiple codes with minimal impact on the area and power requirements of the decoder.

© 2014 Optical Society of America

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References

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  1. A. F. Molisch, Wireless Communications. Wiley, 2005.
  2. J. G. Proakis and M. Salehi, Communication Systems Engineering. Prentice Hall, 1994.
  3. F. Vacondio, O. Rival, Y. Pointurier, C. Simonneau, L. Lorcy, J. Antona, and S. Bigo, “Coherent receiver enabling data rate adaptive optical packet networks,” in European Conf. and Expo. on Optical Communications (ECOC), 2011, pp. 6–8.
  4. F. Vacondio, C. Simonneau, A. Voicila, E. Dutisseuil, J. M. Tanguy, J. C. Antona, G. Charlet, and S. Bigo, “Real time implementation of packet-by-packet polarization demultiplexing in a 28 Gb/s burst mode coherent receiver,” in Optical Fiber Communication Conf., 2012, pp. 57–59.
  5. O. Gerstel and M. Jinno, “Elastic optical networking: A new dawn for the optical layer?” IEEE Commun. Mag., vol.  50, no. 2, pp. s12–s20, Feb.2012.
    [CrossRef]
  6. “Interfaces for the optical transport network (OTN),” , Feb. 2001.
  7. G.-H. Gho, L. Klak, and J. M. Kahn, “Rate-adaptive coding for optical fiber transmission systems,” J. Lightwave Technol., vol.  29, no. 2, pp. 222–233, 2011.
    [CrossRef]
  8. G.-H. Gho and J. M. Kahn, “Rate-adaptive modulation and low-density parity-check coding for optical fiber transmission systems,” J. Opt. Commun. Netw., vol.  4, no. 10, pp. 760–768, Sept. 2012.
    [CrossRef]
  9. C. Dorize, O. Rival, and C. Costantini, “Power scaling of LDPC decoder stage in long haul networks,” in Photonics in Switching, 2012, pp. 2–4.
  10. D. J. C. MacKay, “Good error-correcting codes based on very sparse matrices,” IEEE Trans. Inf. Theory, vol.  45, no. 2, pp. 399–431, Mar. 1999.
    [CrossRef]
  11. S. Lin and D. Costello, Error Control Coding, 2nd ed. Pearson Prentice Hall, 2004.
  12. Y. Miyata, W. Matsumoto, H. Yoshida, T. Mizuochi, and P. Ber, “Efficient FEC for optical communications using concatenated codes to combat error-floor,” in Optical Fiber Communication Conf. and the Nat. Fiber Optic Engineers Conf. (OFC/NFOEC), 2008, pp. 11–13.
  13. A. J. Felstrom and K. S. Zigangirov, “Time-varying periodic convolutional codes with low-density parity-check matrix,” IEEE Trans. Inf. Theory, vol.  45, no. 6, pp. 2181–2191, 1999.
    [CrossRef]
  14. A. E. Pusane, A. Jim, A. Sridharan, M. Lentmaier, K. S. Zigangirov, and D. J. Costello, “Implementation aspects of LDPC convolutional codes,” IEEE Trans. Commun., vol.  56, no. 7, pp. 1060–1069, 2008.
    [CrossRef]
  15. D. Ma and R. Bondade, “Enabling power-efficient DVFS operations on silicon,” IEEE Circuits Syst. Mag., vol.  10, no. 1, pp. 14–30, 2010.
    [CrossRef]
  16. A. S. Sedra and K. C. Smith, Microelectronic Circuits, 4th ed. New York, USA: Oxford University, 1998.
  17. Z. Chen, T. Brandon, and D. Elliott, “Jointly designed architecture-aware LDPC convolutional codes and high-throughput parallel encoders/decoders,” IEEE Trans. Circuits Syst., vol.  57, no. 4, pp. 836–849, 2010.
  18. P. Schlafer, N. Wehn, M. Alles, and T. Lehnigk-Emden, “A new dimension of parallelism in ultra high throughput LDPC decoding,” in IEEE Workshop on Signal Processing Systems, 2013, pp. 153–158.
  19. J. F. Wakerly, Digital Design: Principles and Practices, 3rd ed. New Jersey: Prentice Hall, 2001.

2012 (2)

O. Gerstel and M. Jinno, “Elastic optical networking: A new dawn for the optical layer?” IEEE Commun. Mag., vol.  50, no. 2, pp. s12–s20, Feb.2012.
[CrossRef]

G.-H. Gho and J. M. Kahn, “Rate-adaptive modulation and low-density parity-check coding for optical fiber transmission systems,” J. Opt. Commun. Netw., vol.  4, no. 10, pp. 760–768, Sept. 2012.
[CrossRef]

2011 (1)

2010 (2)

D. Ma and R. Bondade, “Enabling power-efficient DVFS operations on silicon,” IEEE Circuits Syst. Mag., vol.  10, no. 1, pp. 14–30, 2010.
[CrossRef]

Z. Chen, T. Brandon, and D. Elliott, “Jointly designed architecture-aware LDPC convolutional codes and high-throughput parallel encoders/decoders,” IEEE Trans. Circuits Syst., vol.  57, no. 4, pp. 836–849, 2010.

2008 (1)

A. E. Pusane, A. Jim, A. Sridharan, M. Lentmaier, K. S. Zigangirov, and D. J. Costello, “Implementation aspects of LDPC convolutional codes,” IEEE Trans. Commun., vol.  56, no. 7, pp. 1060–1069, 2008.
[CrossRef]

1999 (2)

D. J. C. MacKay, “Good error-correcting codes based on very sparse matrices,” IEEE Trans. Inf. Theory, vol.  45, no. 2, pp. 399–431, Mar. 1999.
[CrossRef]

A. J. Felstrom and K. S. Zigangirov, “Time-varying periodic convolutional codes with low-density parity-check matrix,” IEEE Trans. Inf. Theory, vol.  45, no. 6, pp. 2181–2191, 1999.
[CrossRef]

Alles, M.

P. Schlafer, N. Wehn, M. Alles, and T. Lehnigk-Emden, “A new dimension of parallelism in ultra high throughput LDPC decoding,” in IEEE Workshop on Signal Processing Systems, 2013, pp. 153–158.

Antona, J.

F. Vacondio, O. Rival, Y. Pointurier, C. Simonneau, L. Lorcy, J. Antona, and S. Bigo, “Coherent receiver enabling data rate adaptive optical packet networks,” in European Conf. and Expo. on Optical Communications (ECOC), 2011, pp. 6–8.

Antona, J. C.

F. Vacondio, C. Simonneau, A. Voicila, E. Dutisseuil, J. M. Tanguy, J. C. Antona, G. Charlet, and S. Bigo, “Real time implementation of packet-by-packet polarization demultiplexing in a 28 Gb/s burst mode coherent receiver,” in Optical Fiber Communication Conf., 2012, pp. 57–59.

Ber, P.

Y. Miyata, W. Matsumoto, H. Yoshida, T. Mizuochi, and P. Ber, “Efficient FEC for optical communications using concatenated codes to combat error-floor,” in Optical Fiber Communication Conf. and the Nat. Fiber Optic Engineers Conf. (OFC/NFOEC), 2008, pp. 11–13.

Bigo, S.

F. Vacondio, C. Simonneau, A. Voicila, E. Dutisseuil, J. M. Tanguy, J. C. Antona, G. Charlet, and S. Bigo, “Real time implementation of packet-by-packet polarization demultiplexing in a 28 Gb/s burst mode coherent receiver,” in Optical Fiber Communication Conf., 2012, pp. 57–59.

F. Vacondio, O. Rival, Y. Pointurier, C. Simonneau, L. Lorcy, J. Antona, and S. Bigo, “Coherent receiver enabling data rate adaptive optical packet networks,” in European Conf. and Expo. on Optical Communications (ECOC), 2011, pp. 6–8.

Bondade, R.

D. Ma and R. Bondade, “Enabling power-efficient DVFS operations on silicon,” IEEE Circuits Syst. Mag., vol.  10, no. 1, pp. 14–30, 2010.
[CrossRef]

Brandon, T.

Z. Chen, T. Brandon, and D. Elliott, “Jointly designed architecture-aware LDPC convolutional codes and high-throughput parallel encoders/decoders,” IEEE Trans. Circuits Syst., vol.  57, no. 4, pp. 836–849, 2010.

Charlet, G.

F. Vacondio, C. Simonneau, A. Voicila, E. Dutisseuil, J. M. Tanguy, J. C. Antona, G. Charlet, and S. Bigo, “Real time implementation of packet-by-packet polarization demultiplexing in a 28 Gb/s burst mode coherent receiver,” in Optical Fiber Communication Conf., 2012, pp. 57–59.

Chen, Z.

Z. Chen, T. Brandon, and D. Elliott, “Jointly designed architecture-aware LDPC convolutional codes and high-throughput parallel encoders/decoders,” IEEE Trans. Circuits Syst., vol.  57, no. 4, pp. 836–849, 2010.

Costantini, C.

C. Dorize, O. Rival, and C. Costantini, “Power scaling of LDPC decoder stage in long haul networks,” in Photonics in Switching, 2012, pp. 2–4.

Costello, D.

S. Lin and D. Costello, Error Control Coding, 2nd ed. Pearson Prentice Hall, 2004.

Costello, D. J.

A. E. Pusane, A. Jim, A. Sridharan, M. Lentmaier, K. S. Zigangirov, and D. J. Costello, “Implementation aspects of LDPC convolutional codes,” IEEE Trans. Commun., vol.  56, no. 7, pp. 1060–1069, 2008.
[CrossRef]

Dorize, C.

C. Dorize, O. Rival, and C. Costantini, “Power scaling of LDPC decoder stage in long haul networks,” in Photonics in Switching, 2012, pp. 2–4.

Dutisseuil, E.

F. Vacondio, C. Simonneau, A. Voicila, E. Dutisseuil, J. M. Tanguy, J. C. Antona, G. Charlet, and S. Bigo, “Real time implementation of packet-by-packet polarization demultiplexing in a 28 Gb/s burst mode coherent receiver,” in Optical Fiber Communication Conf., 2012, pp. 57–59.

Elliott, D.

Z. Chen, T. Brandon, and D. Elliott, “Jointly designed architecture-aware LDPC convolutional codes and high-throughput parallel encoders/decoders,” IEEE Trans. Circuits Syst., vol.  57, no. 4, pp. 836–849, 2010.

Felstrom, A. J.

A. J. Felstrom and K. S. Zigangirov, “Time-varying periodic convolutional codes with low-density parity-check matrix,” IEEE Trans. Inf. Theory, vol.  45, no. 6, pp. 2181–2191, 1999.
[CrossRef]

Gerstel, O.

O. Gerstel and M. Jinno, “Elastic optical networking: A new dawn for the optical layer?” IEEE Commun. Mag., vol.  50, no. 2, pp. s12–s20, Feb.2012.
[CrossRef]

Gho, G.-H.

Jim, A.

A. E. Pusane, A. Jim, A. Sridharan, M. Lentmaier, K. S. Zigangirov, and D. J. Costello, “Implementation aspects of LDPC convolutional codes,” IEEE Trans. Commun., vol.  56, no. 7, pp. 1060–1069, 2008.
[CrossRef]

Jinno, M.

O. Gerstel and M. Jinno, “Elastic optical networking: A new dawn for the optical layer?” IEEE Commun. Mag., vol.  50, no. 2, pp. s12–s20, Feb.2012.
[CrossRef]

Kahn, J. M.

Klak, L.

Lehnigk-Emden, T.

P. Schlafer, N. Wehn, M. Alles, and T. Lehnigk-Emden, “A new dimension of parallelism in ultra high throughput LDPC decoding,” in IEEE Workshop on Signal Processing Systems, 2013, pp. 153–158.

Lentmaier, M.

A. E. Pusane, A. Jim, A. Sridharan, M. Lentmaier, K. S. Zigangirov, and D. J. Costello, “Implementation aspects of LDPC convolutional codes,” IEEE Trans. Commun., vol.  56, no. 7, pp. 1060–1069, 2008.
[CrossRef]

Lin, S.

S. Lin and D. Costello, Error Control Coding, 2nd ed. Pearson Prentice Hall, 2004.

Lorcy, L.

F. Vacondio, O. Rival, Y. Pointurier, C. Simonneau, L. Lorcy, J. Antona, and S. Bigo, “Coherent receiver enabling data rate adaptive optical packet networks,” in European Conf. and Expo. on Optical Communications (ECOC), 2011, pp. 6–8.

Ma, D.

D. Ma and R. Bondade, “Enabling power-efficient DVFS operations on silicon,” IEEE Circuits Syst. Mag., vol.  10, no. 1, pp. 14–30, 2010.
[CrossRef]

MacKay, D. J. C.

D. J. C. MacKay, “Good error-correcting codes based on very sparse matrices,” IEEE Trans. Inf. Theory, vol.  45, no. 2, pp. 399–431, Mar. 1999.
[CrossRef]

Matsumoto, W.

Y. Miyata, W. Matsumoto, H. Yoshida, T. Mizuochi, and P. Ber, “Efficient FEC for optical communications using concatenated codes to combat error-floor,” in Optical Fiber Communication Conf. and the Nat. Fiber Optic Engineers Conf. (OFC/NFOEC), 2008, pp. 11–13.

Miyata, Y.

Y. Miyata, W. Matsumoto, H. Yoshida, T. Mizuochi, and P. Ber, “Efficient FEC for optical communications using concatenated codes to combat error-floor,” in Optical Fiber Communication Conf. and the Nat. Fiber Optic Engineers Conf. (OFC/NFOEC), 2008, pp. 11–13.

Mizuochi, T.

Y. Miyata, W. Matsumoto, H. Yoshida, T. Mizuochi, and P. Ber, “Efficient FEC for optical communications using concatenated codes to combat error-floor,” in Optical Fiber Communication Conf. and the Nat. Fiber Optic Engineers Conf. (OFC/NFOEC), 2008, pp. 11–13.

Molisch, A. F.

A. F. Molisch, Wireless Communications. Wiley, 2005.

Pointurier, Y.

F. Vacondio, O. Rival, Y. Pointurier, C. Simonneau, L. Lorcy, J. Antona, and S. Bigo, “Coherent receiver enabling data rate adaptive optical packet networks,” in European Conf. and Expo. on Optical Communications (ECOC), 2011, pp. 6–8.

Proakis, J. G.

J. G. Proakis and M. Salehi, Communication Systems Engineering. Prentice Hall, 1994.

Pusane, A. E.

A. E. Pusane, A. Jim, A. Sridharan, M. Lentmaier, K. S. Zigangirov, and D. J. Costello, “Implementation aspects of LDPC convolutional codes,” IEEE Trans. Commun., vol.  56, no. 7, pp. 1060–1069, 2008.
[CrossRef]

Rival, O.

C. Dorize, O. Rival, and C. Costantini, “Power scaling of LDPC decoder stage in long haul networks,” in Photonics in Switching, 2012, pp. 2–4.

F. Vacondio, O. Rival, Y. Pointurier, C. Simonneau, L. Lorcy, J. Antona, and S. Bigo, “Coherent receiver enabling data rate adaptive optical packet networks,” in European Conf. and Expo. on Optical Communications (ECOC), 2011, pp. 6–8.

Salehi, M.

J. G. Proakis and M. Salehi, Communication Systems Engineering. Prentice Hall, 1994.

Schlafer, P.

P. Schlafer, N. Wehn, M. Alles, and T. Lehnigk-Emden, “A new dimension of parallelism in ultra high throughput LDPC decoding,” in IEEE Workshop on Signal Processing Systems, 2013, pp. 153–158.

Sedra, A. S.

A. S. Sedra and K. C. Smith, Microelectronic Circuits, 4th ed. New York, USA: Oxford University, 1998.

Simonneau, C.

F. Vacondio, C. Simonneau, A. Voicila, E. Dutisseuil, J. M. Tanguy, J. C. Antona, G. Charlet, and S. Bigo, “Real time implementation of packet-by-packet polarization demultiplexing in a 28 Gb/s burst mode coherent receiver,” in Optical Fiber Communication Conf., 2012, pp. 57–59.

F. Vacondio, O. Rival, Y. Pointurier, C. Simonneau, L. Lorcy, J. Antona, and S. Bigo, “Coherent receiver enabling data rate adaptive optical packet networks,” in European Conf. and Expo. on Optical Communications (ECOC), 2011, pp. 6–8.

Smith, K. C.

A. S. Sedra and K. C. Smith, Microelectronic Circuits, 4th ed. New York, USA: Oxford University, 1998.

Sridharan, A.

A. E. Pusane, A. Jim, A. Sridharan, M. Lentmaier, K. S. Zigangirov, and D. J. Costello, “Implementation aspects of LDPC convolutional codes,” IEEE Trans. Commun., vol.  56, no. 7, pp. 1060–1069, 2008.
[CrossRef]

Tanguy, J. M.

F. Vacondio, C. Simonneau, A. Voicila, E. Dutisseuil, J. M. Tanguy, J. C. Antona, G. Charlet, and S. Bigo, “Real time implementation of packet-by-packet polarization demultiplexing in a 28 Gb/s burst mode coherent receiver,” in Optical Fiber Communication Conf., 2012, pp. 57–59.

Vacondio, F.

F. Vacondio, C. Simonneau, A. Voicila, E. Dutisseuil, J. M. Tanguy, J. C. Antona, G. Charlet, and S. Bigo, “Real time implementation of packet-by-packet polarization demultiplexing in a 28 Gb/s burst mode coherent receiver,” in Optical Fiber Communication Conf., 2012, pp. 57–59.

F. Vacondio, O. Rival, Y. Pointurier, C. Simonneau, L. Lorcy, J. Antona, and S. Bigo, “Coherent receiver enabling data rate adaptive optical packet networks,” in European Conf. and Expo. on Optical Communications (ECOC), 2011, pp. 6–8.

Voicila, A.

F. Vacondio, C. Simonneau, A. Voicila, E. Dutisseuil, J. M. Tanguy, J. C. Antona, G. Charlet, and S. Bigo, “Real time implementation of packet-by-packet polarization demultiplexing in a 28 Gb/s burst mode coherent receiver,” in Optical Fiber Communication Conf., 2012, pp. 57–59.

Wakerly, J. F.

J. F. Wakerly, Digital Design: Principles and Practices, 3rd ed. New Jersey: Prentice Hall, 2001.

Wehn, N.

P. Schlafer, N. Wehn, M. Alles, and T. Lehnigk-Emden, “A new dimension of parallelism in ultra high throughput LDPC decoding,” in IEEE Workshop on Signal Processing Systems, 2013, pp. 153–158.

Yoshida, H.

Y. Miyata, W. Matsumoto, H. Yoshida, T. Mizuochi, and P. Ber, “Efficient FEC for optical communications using concatenated codes to combat error-floor,” in Optical Fiber Communication Conf. and the Nat. Fiber Optic Engineers Conf. (OFC/NFOEC), 2008, pp. 11–13.

Zigangirov, K. S.

A. E. Pusane, A. Jim, A. Sridharan, M. Lentmaier, K. S. Zigangirov, and D. J. Costello, “Implementation aspects of LDPC convolutional codes,” IEEE Trans. Commun., vol.  56, no. 7, pp. 1060–1069, 2008.
[CrossRef]

A. J. Felstrom and K. S. Zigangirov, “Time-varying periodic convolutional codes with low-density parity-check matrix,” IEEE Trans. Inf. Theory, vol.  45, no. 6, pp. 2181–2191, 1999.
[CrossRef]

IEEE Circuits Syst. Mag. (1)

D. Ma and R. Bondade, “Enabling power-efficient DVFS operations on silicon,” IEEE Circuits Syst. Mag., vol.  10, no. 1, pp. 14–30, 2010.
[CrossRef]

IEEE Commun. Mag. (1)

O. Gerstel and M. Jinno, “Elastic optical networking: A new dawn for the optical layer?” IEEE Commun. Mag., vol.  50, no. 2, pp. s12–s20, Feb.2012.
[CrossRef]

IEEE Trans. Circuits Syst. (1)

Z. Chen, T. Brandon, and D. Elliott, “Jointly designed architecture-aware LDPC convolutional codes and high-throughput parallel encoders/decoders,” IEEE Trans. Circuits Syst., vol.  57, no. 4, pp. 836–849, 2010.

IEEE Trans. Commun. (1)

A. E. Pusane, A. Jim, A. Sridharan, M. Lentmaier, K. S. Zigangirov, and D. J. Costello, “Implementation aspects of LDPC convolutional codes,” IEEE Trans. Commun., vol.  56, no. 7, pp. 1060–1069, 2008.
[CrossRef]

IEEE Trans. Inf. Theory (2)

A. J. Felstrom and K. S. Zigangirov, “Time-varying periodic convolutional codes with low-density parity-check matrix,” IEEE Trans. Inf. Theory, vol.  45, no. 6, pp. 2181–2191, 1999.
[CrossRef]

D. J. C. MacKay, “Good error-correcting codes based on very sparse matrices,” IEEE Trans. Inf. Theory, vol.  45, no. 2, pp. 399–431, Mar. 1999.
[CrossRef]

J. Lightwave Technol. (1)

J. Opt. Commun. Netw. (1)

Other (11)

P. Schlafer, N. Wehn, M. Alles, and T. Lehnigk-Emden, “A new dimension of parallelism in ultra high throughput LDPC decoding,” in IEEE Workshop on Signal Processing Systems, 2013, pp. 153–158.

J. F. Wakerly, Digital Design: Principles and Practices, 3rd ed. New Jersey: Prentice Hall, 2001.

A. S. Sedra and K. C. Smith, Microelectronic Circuits, 4th ed. New York, USA: Oxford University, 1998.

S. Lin and D. Costello, Error Control Coding, 2nd ed. Pearson Prentice Hall, 2004.

Y. Miyata, W. Matsumoto, H. Yoshida, T. Mizuochi, and P. Ber, “Efficient FEC for optical communications using concatenated codes to combat error-floor,” in Optical Fiber Communication Conf. and the Nat. Fiber Optic Engineers Conf. (OFC/NFOEC), 2008, pp. 11–13.

“Interfaces for the optical transport network (OTN),” , Feb. 2001.

C. Dorize, O. Rival, and C. Costantini, “Power scaling of LDPC decoder stage in long haul networks,” in Photonics in Switching, 2012, pp. 2–4.

A. F. Molisch, Wireless Communications. Wiley, 2005.

J. G. Proakis and M. Salehi, Communication Systems Engineering. Prentice Hall, 1994.

F. Vacondio, O. Rival, Y. Pointurier, C. Simonneau, L. Lorcy, J. Antona, and S. Bigo, “Coherent receiver enabling data rate adaptive optical packet networks,” in European Conf. and Expo. on Optical Communications (ECOC), 2011, pp. 6–8.

F. Vacondio, C. Simonneau, A. Voicila, E. Dutisseuil, J. M. Tanguy, J. C. Antona, G. Charlet, and S. Bigo, “Real time implementation of packet-by-packet polarization demultiplexing in a 28 Gb/s burst mode coherent receiver,” in Optical Fiber Communication Conf., 2012, pp. 57–59.

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Figures (14)

Fig. 1.
Fig. 1.

Simulation showing the BER before and after RS FEC decoding as a function of the SNR.

Fig. 2.
Fig. 2.

BER after RS FEC decoding as a function of the input BER assuming the worst case scenario of uncorrelated (nonbursty) errors at the input.

Fig. 3.
Fig. 3.

Standard OTN frame [6].

Fig. 4.
Fig. 4.

Proposed variable rate frame structure. Here the FAS field is followed by a special CI field. The length of the frame depends on the inner FEC code, which can be determined from the CI.

Fig. 5.
Fig. 5.

Code word error rate versus SNR. The hard decision and the soft decision (SD) estimate curves are based on analytical calculations of the expected error rate. The 4-bit SD simulation shows the actual error correcting capabilities of the decoding algorithm simulated in Matlab using 4-bit soft decision resolution.

Fig. 6.
Fig. 6.

OTN frame alignment state diagram.

Fig. 7.
Fig. 7.

Average number of frames to obtain FA for different values of acceptable FAS error (e). The best case is 2 frames, as defined by the standard OTN frame alignment state machine.

Fig. 8.
Fig. 8.

Overall system schematic. Extra modules have been appended to a standard OTN system to allow for adaptive SD (FEC).

Fig. 9.
Fig. 9.

Simulation of the normalized dynamic FEC power consumption. At zero LDPC iterations, only the hard-decision RS FEC consumes power.

Fig. 10.
Fig. 10.

Pipelined iterative FEC with dynamic iteration reduction (control signals not shown).

Fig. 11.
Fig. 11.

Necessary number of iterations for achieving BER104 for each code rate.

Fig. 12.
Fig. 12.

Normalized power consumption, taking into account frequency and voltage reduction, and complexity increase due to a lower rate, for each rate, achieving the desired threshold of BER<104.

Fig. 13.
Fig. 13.

True and estimated BER performance of an LDPC-CC with R=(1/2), M=257, k=61,440 with zero-padding termination.

Fig. 14.
Fig. 14.

Probability of erroneous halt and effective BER estimation error for the LDPC-CC with R=(1/2), M=257, k=61,440.

Tables (1)

Tables Icon

TABLE I List of FAS/CI Code Wordsa

Equations (9)

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

p(b=1)=11+eLb,p(b=0)=11+eLb.
pe=p(bt=1)p(b=0)+p(bt=0)p(b=1).
pe={1211+eLb,Lb01211+eLb,Lb0.
pe=11+exp(|Lb|).
Rtrue=kcbk+c(M+1)<bc.
1i=0k(1P)(ni)·Pi·(ni),
PBi=1nAiQ(2i·SNR),
PBAdminQ(2dmin·SNR).
Eav=Σn=1N|true_BERnest_BERn|N,