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- Fan, Yuchuan, et al.
(författare)
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EVM Estimation for Performance Monitoring in Coherent Optical Systems : An Approach of Linear Regression
- 2022
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Ingår i: Optics InfoBase Conference Papers. - : Optica Publishing Group (formerly OSA). - 9781557528209
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Konferensbidrag (refereegranskat)abstract
- We experimentally demonstrate the effectiveness of a simple linear regression scheme for optical performance monitoring when applied after modulation format identification. It outperforms the FFNN-based benchmark scheme providing 0.2% mean absolute error for EVM estimation., © 2022 The Author(s)
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- Fan, Yuchuan, et al.
(författare)
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Experimental validation of CNNs versus FFNNs for time- and energy-efficient EVM estimation in coherent optical systems
- 2021
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Ingår i: Journal of Optical Communications and Networking. - : OPTICAL SOC AMER. - 1943-0620 .- 1943-0639. ; 13:10, s. E63-E71
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Tidskriftsartikel (refereegranskat)abstract
- Error vector magnitude (EVM) has proven to be one of the optical performance monitoring metrics providing the quantitative estimation of error statistics. However, the EVM estimation efficiency has not been fully exploited in terms of complexity and energy consumption. Therefore, in this paper, we explore two deep-learning-based EVM estimation schemes. The first scheme exploits convolutional neural networks (CNNs) to extract EVM information from images of the constellation diagram in the in-phase/quadrature (IQ) complex plane or amplitude histograms (AHs). The second scheme relies on feedforward neural networks (FFNNs) extracting features from a vectorized representation of AHs. In both cases, we use short sequences of 32 Gbaud m-ary quadrature amplitude modulation (mQAM) signals captured before or after a carrier phase recovery. The impacts of the sequence length, neural network structure, and data set representation on the EVM estimation accuracy as well as the model training time are thoroughly studied. Furthermore, we validate the performance of the proposed schemes using the experimental implementation of 28 Gbaud 64QAM signals. We achieve a mean absolute estimation error below 0.15%, with short signals consisting of only 100 symbols per IQ cluster. Considering the estimation accuracy, the implementation complexity, and the potential energy savings, the proposed CNN- and FFNN-based schemes can be used to perform time-sensitive and accurate EVM estimation for mQAM signal quality monitoring purposes.
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- Gaiarin, Simone, et al.
(författare)
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High speed PAM-8 optical interconnects with digital equalization based on neural network
- 2016
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Ingår i: Asia Communications and Photonics Conference 2016. - : Optical Society of America.
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Konferensbidrag (refereegranskat)abstract
- We experimentally evaluate a high-speed optical interconnection link with neural network equalization. Enhanced equalization performances are shown comparing to standard linear FFE for an EML-based 32 GBd PAM-8 signal after 4-km SMF transmission.
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- Navarro, Jaime Rodrigo, et al.
(författare)
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Two-Stage n-PSK Partitioning Carrier Phase Recovery Scheme for Circular mQAM Coherent Optical Systems
- 2016
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Ingår i: Photonics. - : MDPI AG. - 2304-6732. ; 3:2
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Tidskriftsartikel (refereegranskat)abstract
- A novel two-stage n-PSK partitioning carrier phase recovery (CPR) scheme for circular multilevel quadrature amplitude modulation (C-mQAM) constellations is presented. The first stage of the algorithm provides an initial rough estimation of the received constellation, which is utilized in the second stage for CPR. The performance of the proposed algorithm is studied through extensive simulations at the forward error correction bit error rate targets of 3.8 x 10(-3) and 1 x 10(-2) and is compared with different CPR algorithms. A significant improvement in the combined linewidth symbol duration product (Delta vT(s)) tolerance is achieved compared to the single-stage n-PSK partitioning scheme. Superior performance in the Delta vT(s) tolerance compared to the blind phase search algorithm is also reported. The relative improvements with respect to other CPR schemes are also validated experimentally for a 28-Gbaud C-16QAM back-to-back transmission system. The computational complexity of the proposed CPR scheme is studied, and reduction factors of 24.5 broken vertical bar 30.1 and 59.1 broken vertical bar 63.3 are achieved for C-16QAM and C-64QAM, respectively, compared to single-stage BPS in the form of multipliers broken vertical bar adders.
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- Ozolins, Oskars, et al.
(författare)
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Optical spectral reshaping for directly modulated 4-pulse amplitude modulation signals
- 2017
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Ingår i: Transparent Optical Networks (ICTON), 2017 19th International Conference on. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538608609 ; , s. 1-1
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Konferensbidrag (refereegranskat)abstract
- The tremendous traffic growth in intra/inter-datacenters requires low-cost high-speed integrated solutions [1]. To enable a significantly reduced footprint directly modulated lasers (DMLs) have been proposed instead of large external modulators. However, it is challenging to use DMLs due to their low dispersion tolerance and limited achievable extinction ratio (ER). A promising solution to this problem is optical spectral reshaping (OSR) since it is possible to increase the dispersion tolerance as well as to enhance the achievable ER for both on-of-keying [2] and 4-pulse amplitude modulation (PAM) [3] signals. However, moving to 4-PAM,many of the impressive demonstrations reported so far rely heavily on off-line digital signal processing (DSP), which increases latency, power consumption and cost. In this talk, we report on (i) a detailed numerical analysis on the complex transfer function of the optical filter for optical spectral reshaping in case of pulse amplitude modulation and(ii) an experimental demonstration of real-time dispersion-uncompensated transmission of 10-GBd and 14-GBd 4-PAM signals up to 10- and 26-km SSMF. This is achieved by combining a commercial 10-Gb/s DML with optical spectral shaping, thus removing the need for any complex off-line DSP and improving dispersion tolerance. These achievements are enabled by OSR based on a passive microring resonator fabricated on the SOI platform [4]. Significant improvement in receiver sensitivities was observed for both a 10-GBd signal after 10-km SSMF transmission and 14-GBd with no penalty after 26-km SSMF transmission.
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