A Simplified Volterra Equalizer Based on System Characteristics for Direct Modulation Laser (DML)-Based Intensity Modulation and Direct Detection (IM/DD) Transmission Systems
The nonlinear Volterra equalizer has been proved to be able to solve the problem of nonlinear distortion, but it has high computational complexity and is difficult to implement. In this paper, a simplified second-order Volterra nonlinear equalizer designed for intensity modulation/direct detection s...
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| Format: | Article |
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MDPI AG
2023-10-01
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| Series: | Photonics |
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| Online Access: | https://www.mdpi.com/2304-6732/10/10/1174 |
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| author | Zhongshuai Feng Na Li Wei Li Peili He Ming Luo Qianggao Hu Liyan Huang Yi Jiang |
| author_facet | Zhongshuai Feng Na Li Wei Li Peili He Ming Luo Qianggao Hu Liyan Huang Yi Jiang |
| author_sort | Zhongshuai Feng |
| collection | DOAJ |
| description | The nonlinear Volterra equalizer has been proved to be able to solve the problem of nonlinear distortion, but it has high computational complexity and is difficult to implement. In this paper, a simplified second-order Volterra nonlinear equalizer designed for intensity modulation/direct detection systems based on direct modulated laser is proposed and demonstrated, taking into account the characteristics of the system. It has been proved that the received signal of direct modulation laser/direct detection system can be expressed in Volterra series form, but its form is too complex, and the device parameters should also be considered. We re-derived it and obtained a more concise form. At the same time, we proposed a method to simplify the second-order Volterra nonlinear equalizer without relying on device parameters. The performance of the proposed Volterra nonlinear equalizer is evaluated experimentally on a 56 Gb/s 4-ary pulse amplitude modulation link implemented by using a 1.55 µm direct modulation laser. The results show that, compared with the traditional Volterra nonlinear equalizer, the receiver sensitivity of the equalizer is only reduced by 0.2 dB at most, but the complexity can be reduced by 50%; compared with diagonally pruned Volterra nonlinear equalizers, the complexity of the equalizer is the same, but the reception sensitivity can be improved by 0.5 dB. |
| first_indexed | 2024-03-10T20:57:42Z |
| format | Article |
| id | doaj.art-83df0ceb1e9447789e933704608d4ddd |
| institution | Directory Open Access Journal |
| issn | 2304-6732 |
| language | English |
| last_indexed | 2024-03-10T20:57:42Z |
| publishDate | 2023-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Photonics |
| spelling | doaj.art-83df0ceb1e9447789e933704608d4ddd2023-11-19T17:48:05ZengMDPI AGPhotonics2304-67322023-10-011010117410.3390/photonics10101174A Simplified Volterra Equalizer Based on System Characteristics for Direct Modulation Laser (DML)-Based Intensity Modulation and Direct Detection (IM/DD) Transmission SystemsZhongshuai Feng0Na Li1Wei Li2Peili He3Ming Luo4Qianggao Hu5Liyan Huang6Yi Jiang7Wuhan National Laboratory for Optoelectronic, Huazhong University of Science and Technology, Wuhan 430074, ChinaWuhan National Laboratory for Optoelectronic, Huazhong University of Science and Technology, Wuhan 430074, ChinaWuhan National Laboratory for Optoelectronic, Huazhong University of Science and Technology, Wuhan 430074, ChinaWuhan National Laboratory for Optoelectronic, Huazhong University of Science and Technology, Wuhan 430074, ChinaState Key Laboratory of Optical Communication Technologies and Networks, Wuhan 430200, ChinaAccelink Technologies Co., Ltd., Wuhan 430205, ChinaAccelink Technologies Co., Ltd., Wuhan 430205, ChinaAccelink Technologies Co., Ltd., Wuhan 430205, ChinaThe nonlinear Volterra equalizer has been proved to be able to solve the problem of nonlinear distortion, but it has high computational complexity and is difficult to implement. In this paper, a simplified second-order Volterra nonlinear equalizer designed for intensity modulation/direct detection systems based on direct modulated laser is proposed and demonstrated, taking into account the characteristics of the system. It has been proved that the received signal of direct modulation laser/direct detection system can be expressed in Volterra series form, but its form is too complex, and the device parameters should also be considered. We re-derived it and obtained a more concise form. At the same time, we proposed a method to simplify the second-order Volterra nonlinear equalizer without relying on device parameters. The performance of the proposed Volterra nonlinear equalizer is evaluated experimentally on a 56 Gb/s 4-ary pulse amplitude modulation link implemented by using a 1.55 µm direct modulation laser. The results show that, compared with the traditional Volterra nonlinear equalizer, the receiver sensitivity of the equalizer is only reduced by 0.2 dB at most, but the complexity can be reduced by 50%; compared with diagonally pruned Volterra nonlinear equalizers, the complexity of the equalizer is the same, but the reception sensitivity can be improved by 0.5 dB.https://www.mdpi.com/2304-6732/10/10/1174direct detectionintensity modulationnonlinear equalizationPAM4Volterra filter |
| spellingShingle | Zhongshuai Feng Na Li Wei Li Peili He Ming Luo Qianggao Hu Liyan Huang Yi Jiang A Simplified Volterra Equalizer Based on System Characteristics for Direct Modulation Laser (DML)-Based Intensity Modulation and Direct Detection (IM/DD) Transmission Systems Photonics direct detection intensity modulation nonlinear equalization PAM4 Volterra filter |
| title | A Simplified Volterra Equalizer Based on System Characteristics for Direct Modulation Laser (DML)-Based Intensity Modulation and Direct Detection (IM/DD) Transmission Systems |
| title_full | A Simplified Volterra Equalizer Based on System Characteristics for Direct Modulation Laser (DML)-Based Intensity Modulation and Direct Detection (IM/DD) Transmission Systems |
| title_fullStr | A Simplified Volterra Equalizer Based on System Characteristics for Direct Modulation Laser (DML)-Based Intensity Modulation and Direct Detection (IM/DD) Transmission Systems |
| title_full_unstemmed | A Simplified Volterra Equalizer Based on System Characteristics for Direct Modulation Laser (DML)-Based Intensity Modulation and Direct Detection (IM/DD) Transmission Systems |
| title_short | A Simplified Volterra Equalizer Based on System Characteristics for Direct Modulation Laser (DML)-Based Intensity Modulation and Direct Detection (IM/DD) Transmission Systems |
| title_sort | simplified volterra equalizer based on system characteristics for direct modulation laser dml based intensity modulation and direct detection im dd transmission systems |
| topic | direct detection intensity modulation nonlinear equalization PAM4 Volterra filter |
| url | https://www.mdpi.com/2304-6732/10/10/1174 |
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