ZTE Communications ›› 2012, Vol. 10 ›› Issue (3): 2-11.

• Special Topic • Previous Articles     Next Articles

FSK Modulation Scheme for High-Speed Optical Transmission

Nan Chi, Wuliang Fang, Yufeng Shao, Junwen Zhang, and Li Tao   

  1. State Key Lab of ASIC & System, and Department of Communication Science and Engineering, Fudan University, Shanghai 200433, China
  • Received:2011-11-30 Online:2012-09-25 Published:2012-09-25
  • About author:Nan Chi (nanchi@fudan.edu.cn) received her BS and PhD degrees in electrical engineering from Beijing University of Posts and Telecommunications in 1996 and 2001. From July 2001 to December 2004, she worked as assistant professor at the Research Center COM, Technical University of Denmark, Lyngby. From January 2005 to April 2006, she was a research associate at the University of Bristol, UK. In June 2006, she joined the Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology. There, she worked as a full professor. She joined the School of Information Science and Engineering, Fudan University, in June 2008. She is the author or co-author of more than 150 papers and the co-holder of two US patents. She has given seven invited talks in international conferences and workshops. She was chair of the optical switching and routing technologies workshop at the Asia-Pacific Optical Conference 2007, and she was the local committee chair of ACP 2010. She has received a New Century Excellent Talent Award from the Education Ministry of China in 2006 and the Shuguang Scholarship in 2009. Her research interests include optical packet/burst switching, all-optical processing, and advanced modulation formats.

    Wuliang Fang (fangwuliang2005@163.com) received his BS degree in optical information and technology from Huazhong University of Science and Technology, Wuhan, China, in 2009. Since 2009, he has been studying for his master's degree in the Department of Communication Science and Engineering, Fudan University. His research interests include multimode fiber theories, spatial multiplexing, coherent optical communication, and signal processing.

    Yufeng Shao (shaoyufeng@fudan.edu.cn) received his BS and ME degrees from Chongqing University of Post and Communications, China, in 2000 and 2005. He received his PhD degree from Hunan University, China, in 2009. He is currently a postdoctoral researcher and lecturer at the State Key Lab of ASIC & Systems, and also at the Department of Communication Science and Engineering, Fudan University, Shanghai. From April 2011 to August 2011, he was a research associate at Hong Kong Polytechnic University. His research interests include new modulation format techniques, all-optical signal processing, optical label switching, and optical OFDM technology. He has authored or coauthored more than 80 publications in international journals and at conferences. He holds one Chinese patent and has five Chinese patents pending.

    Junwen Zhang (hustzjw@gmail.com) received his BS degree in optical information and technology from Huazhong University of Science and Technology, Wuhan, China, in 2009. Since 2009, he has been studying for his PhD degree in the Department of Communication Science and Engineering, Fudan University. His research interests include high-speed optical transmission, coherent optical communication, and signal processing.

    Li Tao (taoli522930@gmail.com) received his BS degree in optical information and technology from Huazhong University of Science and Technology, Wuhan, China, in 2010. Since 2010, he has been studying for his PhD degree in the Department of Communication Science and Engineering, Fudan University. His research interests include high-speed optical transmission, coherent optical communication, OFDM, and signal processing.

FSK Modulation Scheme for High-Speed Optical Transmission

Nan Chi, Wuliang Fang, Yufeng Shao, Junwen Zhang, and Li Tao   

  1. State Key Lab of ASIC & System, and Department of Communication Science and Engineering, Fudan University, Shanghai 200433, China
  • 作者简介:Nan Chi (nanchi@fudan.edu.cn) received her BS and PhD degrees in electrical engineering from Beijing University of Posts and Telecommunications in 1996 and 2001. From July 2001 to December 2004, she worked as assistant professor at the Research Center COM, Technical University of Denmark, Lyngby. From January 2005 to April 2006, she was a research associate at the University of Bristol, UK. In June 2006, she joined the Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology. There, she worked as a full professor. She joined the School of Information Science and Engineering, Fudan University, in June 2008. She is the author or co-author of more than 150 papers and the co-holder of two US patents. She has given seven invited talks in international conferences and workshops. She was chair of the optical switching and routing technologies workshop at the Asia-Pacific Optical Conference 2007, and she was the local committee chair of ACP 2010. She has received a New Century Excellent Talent Award from the Education Ministry of China in 2006 and the Shuguang Scholarship in 2009. Her research interests include optical packet/burst switching, all-optical processing, and advanced modulation formats.

    Wuliang Fang (fangwuliang2005@163.com) received his BS degree in optical information and technology from Huazhong University of Science and Technology, Wuhan, China, in 2009. Since 2009, he has been studying for his master's degree in the Department of Communication Science and Engineering, Fudan University. His research interests include multimode fiber theories, spatial multiplexing, coherent optical communication, and signal processing.

    Yufeng Shao (shaoyufeng@fudan.edu.cn) received his BS and ME degrees from Chongqing University of Post and Communications, China, in 2000 and 2005. He received his PhD degree from Hunan University, China, in 2009. He is currently a postdoctoral researcher and lecturer at the State Key Lab of ASIC & Systems, and also at the Department of Communication Science and Engineering, Fudan University, Shanghai. From April 2011 to August 2011, he was a research associate at Hong Kong Polytechnic University. His research interests include new modulation format techniques, all-optical signal processing, optical label switching, and optical OFDM technology. He has authored or coauthored more than 80 publications in international journals and at conferences. He holds one Chinese patent and has five Chinese patents pending.

    Junwen Zhang (hustzjw@gmail.com) received his BS degree in optical information and technology from Huazhong University of Science and Technology, Wuhan, China, in 2009. Since 2009, he has been studying for his PhD degree in the Department of Communication Science and Engineering, Fudan University. His research interests include high-speed optical transmission, coherent optical communication, and signal processing.

    Li Tao (taoli522930@gmail.com) received his BS degree in optical information and technology from Huazhong University of Science and Technology, Wuhan, China, in 2010. Since 2010, he has been studying for his PhD degree in the Department of Communication Science and Engineering, Fudan University. His research interests include high-speed optical transmission, coherent optical communication, OFDM, and signal processing.

Abstract: In this paper, we describe the generation, detection, and performance of frequency-shift keying (FSK) for high-speed optical transmission and label switching. A non-return-to-zero (NRZ) FSK signal is generated by using two continuous-wave (CW) lasers, one Mach-Zehnder modulator (MZM), and one Mach-Zehnder delay interferometer (MZDI). An RZ-FSK signal is generated by cascading a dual-arm MZM, which is driven by a sinusoidal voltage at half the bit rate. Demodulation can be achieved on 1 bit rate through one MZDI or an array waveguide grating (AWG) demultiplexer with balanced detection. We perform numerical simulation on two types of frequency modulation schemes using MZM or PM, and we determine the effect of frequency tone spacing (FTS) on the generated FSK signal. In the proposed scheme, a novel frequency modulation format has transmission advantages compared with traditional modulation formats such as RZ and differential phase-shift keying (DPSK), under varying dispersion management. The performance of an RZ-FSK signal in a 4 × 40 Gb/s WDM transmission system is discussed. We experiment on transparent wavelength conversion based on four-wave mixing (FWM) in a semiconductor optical amplifier (SOA) and in a highly nonlinear dispersion shifted fiber (HNDSF) for a 40 Gb/s RZ-FSK signal. The feasibility of all-optical signal processing of a high-speed RZ-FSK signal is confirmed. We also determine the receiver power penalty for the RZ-FSK signal after a 100 km standard single-mode fiber (SMF) transmission link with matching dispersion compensating fiber (DCF), under the post-compensation management scheme. Because the frequency modulation format is orthogonal to intensity modulation and vector modulation (polarization shift keying), it can be used in the context of the combined modulation format to decrease the data rate or enhance the symbol rate. It can also be used in orthogonal label-switching as the modulation format for the payload or the label. As an example, we propose a simple orthogonal optical label switching technique based on 40 Gb/s FSK payload and 2.5 Gb/s intensity modulated (IM) label.

Key words: optical communication, return-to-zero frequency shift keying, Mach-Zehnder modulator, Mach-Zehnder delay interferometer, chromatic dispersion, wavelength conversion, label switching

摘要: In this paper, we describe the generation, detection, and performance of frequency-shift keying (FSK) for high-speed optical transmission and label switching. A non-return-to-zero (NRZ) FSK signal is generated by using two continuous-wave (CW) lasers, one Mach-Zehnder modulator (MZM), and one Mach-Zehnder delay interferometer (MZDI). An RZ-FSK signal is generated by cascading a dual-arm MZM, which is driven by a sinusoidal voltage at half the bit rate. Demodulation can be achieved on 1 bit rate through one MZDI or an array waveguide grating (AWG) demultiplexer with balanced detection. We perform numerical simulation on two types of frequency modulation schemes using MZM or PM, and we determine the effect of frequency tone spacing (FTS) on the generated FSK signal. In the proposed scheme, a novel frequency modulation format has transmission advantages compared with traditional modulation formats such as RZ and differential phase-shift keying (DPSK), under varying dispersion management. The performance of an RZ-FSK signal in a 4 × 40 Gb/s WDM transmission system is discussed. We experiment on transparent wavelength conversion based on four-wave mixing (FWM) in a semiconductor optical amplifier (SOA) and in a highly nonlinear dispersion shifted fiber (HNDSF) for a 40 Gb/s RZ-FSK signal. The feasibility of all-optical signal processing of a high-speed RZ-FSK signal is confirmed. We also determine the receiver power penalty for the RZ-FSK signal after a 100 km standard single-mode fiber (SMF) transmission link with matching dispersion compensating fiber (DCF), under the post-compensation management scheme. Because the frequency modulation format is orthogonal to intensity modulation and vector modulation (polarization shift keying), it can be used in the context of the combined modulation format to decrease the data rate or enhance the symbol rate. It can also be used in orthogonal label-switching as the modulation format for the payload or the label. As an example, we propose a simple orthogonal optical label switching technique based on 40 Gb/s FSK payload and 2.5 Gb/s intensity modulated (IM) label.

关键词: optical communication, return-to-zero frequency shift keying, Mach-Zehnder modulator, Mach-Zehnder delay interferometer, chromatic dispersion, wavelength conversion, label switching