Single-step digital backpropagation for nonlinearity mitigation

Secondini, Marco; Rommel, Simon; Meloni, G.; Fresi, Francesco; Forestieri, E.; Potì, L.

doi:10.1007/s11107-015-0586-z

Cited by 35 publications

(42 citation statements)

References 29 publications

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“…It should be noted that the optimum launch power increased to -2.5 dBm for both the DP-QPSK and DP-16QAM cases. These two results together give confidence in the effective operation of the ESSFM, and are comparable to the original results for this algorithm as presented in [10].…”

Section: B Enhanced Split Step Fourier Methodssupporting

confidence: 83%

“…The signal was sampled at 4 samples/symbol and shaped using a root-raise cosine (RRC) filter. In this approach, we numerically solved the Manakov system for forward pulse propagation to simulate 1000 km (25×40 km span) of standard singlemode fiber (SSMF), as a representative long-haul transmission system, and following the methodology in [10]. An EDFA was included after each span to fully compensate for the power loss due to signal attenuation over the span.…”

Section: A Algorithm Designmentioning

confidence: 99%

“…This blind optimization approach uses gradient descent with a relative tolerance of 10 −3 to converge on a set of filter coefficients. Similarly to [10], we applied nonlinear optimization to maximize the SNR of a sample sequence using the coefficients, c i as the degrees of freedom. The number of coefficients in the filter was restricted to a power of two, again for direct comparison with [10].…”

Section: A Algorithm Designmentioning

confidence: 99%

“…Here, this investigation was repeated for our system parameters, as it can be seen that additional multiplications in theN operator have implications for the performance limitations from the quantization overhead in the fixed point model; there is a trade off between nonlinear performance gain and quantization noise introduced from the additional filter taps. The theoretical basis for the operation of the ESSFM and the filter coefficients is further discussed in [10], [17]. As the ESSFM operates at the 1 step-per-link level, the Wiener-Hammerstein (WH) split now determines the position of the only nonlinearity compensation operator across all spans.…”

Section: A Algorithm Designmentioning

confidence: 99%

See 3 more Smart Citations

On the Impact of Fixed Point Hardware for Optical Fiber Nonlinearity Compensation Algorithms

Sherborne

Banks

Semrau

et al. 2018

J. Lightwave Technol.

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Nonlinearity mitigation using digital signal processing has been shown to increase the achievable data rates of optical fiber transmission links. One especially effective technique is digital back propagation (DBP), an algorithm capable of simultaneously compensating for linear and nonlinear channel distortions. The most significant barrier to implementing this technique, however, is its high computational complexity. In recent years, there have been several proposed alternatives to DBP with reduced computational complexity, although such techniques have not demonstrated performance benefits commensurate with the complexity of implementation. In order to fully characterize the computational requirements of DBP, there is a need to model the algorithm behavior when constrained to the logic used in a digital coherent receiver. Such a model allows for the analysis of any signal recovery algorithm in terms of true hardware complexity which, crucially, includes the bit-depth of the multiplication operation. With a limited bit depth, there is quantization noise, introduced with each arithmetic operation, and it can no longer be assumed that the conventional DBP algorithm will outperform its low complexity alternatives. In this work, DBP and a single nonlinear step DBP implementation, the Enhanced Split Step Fourier method (ESSFM), were compared with linear equalization using a generic software model of fixed point hardware. The requirements of bit depth and fast Fourier transform (FFT) size are discussed to examine the optimal operating regimes for these two schemes of digital nonlinearity compensation. For a 1000 km transmission system, it was found that (assuming an optimized FFT size), in terms of SNR, the ESSFM algorithm outperformed the conventional DBP for all hardware resolutions up to 13 bits.

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Section: B Enhanced Split Step Fourier Methodssupporting

confidence: 83%

Section: A Algorithm Designmentioning

confidence: 99%

Section: A Algorithm Designmentioning

confidence: 99%

Section: A Algorithm Designmentioning

confidence: 99%

See 2 more Smart Citations

On the Impact of Fixed Point Hardware for Optical Fiber Nonlinearity Compensation Algorithms

Sherborne

Banks

Semrau

et al. 2018

J. Lightwave Technol.

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“…V, the minimum value of N for DBP is dictated by the targeted NLC performance and the channel memory (see e.g. [35]). Due the logarithmic scaling of simplified VSFE, matching an increasing channel memory by increasing N only results in a minor complexity increase, which is also the case for DBP.…”

Section: Complexitymentioning

confidence: 99%

Volterra-Assisted Optical Phase Conjugation: A Hybrid Optical-Digital Scheme for Fiber Nonlinearity Compensation

Saavedra

Liga

Bayvel

2019

J. Lightwave Technol.

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Mitigation of optical fiber nonlinearity is an active research field in the area of optical communications, due to the resulting marked improvement in transmission performance. Following the resurgence of optical coherent detection, digital nonlinearity compensation (NLC) schemes such as digital backpropagation (DBP) and Volterra equalization have received much attention. Alternatively, optical NLC, and specifically optical phase conjugation (OPC), has been proposed to relax the digital signal processing complexity.In this work, a novel hybrid optical-digital NLC scheme combining OPC and a Volterra equalizer is proposed, termed Volterra-Assisted OPC (VAO). It has a twofold advantage: it overcomes the OPC limitation in asymmetric links and substantially enhances the performance of Volterra equalizers. The proposed scheme is shown to outperform both OPC and Volterra equalization alone by up to 4.2 dB in a 1000 km EDFA-amplified fiber link. Moreover, VAO is also demonstrated to be very robust when applied to long-transmission distances, with a 2.5 dB gain over OPC-only systems at 3000 km.VAO combines the advantages of both optical and digital NLC offering a promising trade-off between performance and complexity for future high-speed optical communication systems.

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Alleviation of nonlinear channel effects in long‐haul and high‐capacity optical transmission networks

Ali

Habib

Muhammad

et al. 2021

Int J Communication

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Summary Optical transmission networks (OTxNs) provide a cost‐effective solution towards ultrahigh data intercontinental transmission. However, nonlinear effects such as four‐wave mixing (FWM) and cross‐phase modulation (XPM) are the major performance limiting factors for OTxNs. This paper proposes the use of differential quadrature phase shift keying (DQPSK) modulation format and uneven channel spacings for dispersion compensation and investigates the nonlinear mitigation performance for a 32 channels ultradense wavelength division multiplexing (UDWDM) with data rate of up to 10 Gbps per channel. In addition, this paper presents an analysis on power budget and power penalties with a cost benefit analysis (CBA) for the proposed framework. The transmission link of the proposed UDWDM model is analyzed in terms of bit error rate (BER) for various lengths of optical fiber in long‐haul transmission, launch power, nonlinear effective area, and nonlinear refractive index. The analytical model is developed for mitigation of nonlinearity for the modeled UDWDM long‐haul and ultrahigh‐capacity system, beyond 1200‐km path span. The simulation results show systems advantages of having narrower spectrum than on‐off‐keying (OOK) modulation, significant tolerance to nonlinearities and low cost, compared with current OTxNs with 2.8‐dB optical signal‐to‐noise ratio (OSNR) improvement and successful mitigation of nonlinearities for as high launch powers as +4 dBm for such long distance transmission in dispersive channel.

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Single-step digital backpropagation for nonlinearity mitigation

Cited by 35 publications

References 29 publications

On the Impact of Fixed Point Hardware for Optical Fiber Nonlinearity Compensation Algorithms

On the Impact of Fixed Point Hardware for Optical Fiber Nonlinearity Compensation Algorithms

Volterra-Assisted Optical Phase Conjugation: A Hybrid Optical-Digital Scheme for Fiber Nonlinearity Compensation

Alleviation of nonlinear channel effects in long‐haul and high‐capacity optical transmission networks

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