一种全光正交频分复用系统及其器件
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摘要
本论文提出了一种新颖的全光正交频分复用(OFDM,Orthogonal Frequency Division Multiplexing)系统,研究了该系统中基于光耦合器的光离散傅里叶变换(DFT,Discrete Fourier Transform)器件。
OFDM对于无线和铜线的应用,已经是成熟的技术,而在光通信上的应用,却还是比较晚的事。但OFDM的光传输是一个快速发展的研究领域。在非全光OFDM系统中,容量受限于两个主要方面:光数据调制器、光电二极管,和快速傅里叶变换(FFT,Fast Fourier Transform)的电路。而在全光OFDM系统中,FFT以光的方式实现,传输数据率就会大大提高。全光OFDM技术有着很大吸引力,作为以后的大容量、高频谱效率、长距离通信系统的有力候选技术。
本论文首先对OFDM原理在数学上进行了分析,并根据无线应用中OFDM系统的基本功能,讨论了OFDM的关键技术。
然后针对全光OFDM系统,本论文采用了一种基于光耦合器的DFT器件。根据光耦合器的输入输出关系,给它加上适当相移,可以实现两个点的DFT,并作为光DFT基本单元。然后按照FFT算法的思想,用基本单元构造出了N (2的整数次幂)个点的DFT器件。并给出了具体的实现结构和基于平面光路(PLC,Planar Lightwave Circuit)的仿真。
接着提出了基于上述器件的全光OFDM系统,对系统的各个部分及其工作过程做出了细致的说明。对这种全光OFDM系统在160Gbit/s速率下进行了仿真,结果表明接收端的误码率为7.958×10~(-10),接收机前的光信噪比为24.97dB。并进行了性能仿真,主要是分析了不同调制方式下色散和噪声的特性,以及非线性对全光OFDM的影响。
This thesis proposes a novel all-optical Orthogonal Frequency Division Multiplexing (OFDM) transmission system, and studies optical Discrete Fourier Transform (DFT) devices based on optical couplers in this system.
OFDM has been established as a mature technology for applications of wireless and copper, while it is lately applied to optical communication. But optical transmission by OFDM is the fastest growing area in recent years. In not-all-optical OFDM system, the capacity is limited by two major components: the optical data modulator and the photodiode, and electronics for FFT. While in all-optical one, the FFT process is achieved in optical domain, the OFDM transmission data rate can be increased by far. All-optical OFDM becomes an attractive candidate for high capacity, frequency effective, long haul communication systems.
This thesis firstly analyses the mathematical principle of OFDM, and discusses key technologies related to basic functions of wireless OFDM system.
Then, this thesis applies a kind of optical DFT devices based on optical couplers in accordance with all-optical OFDM system. And shows that one coupler can act as a 2×2 DFT device when combined with appropriate phase shift, owing to the relationship between its inputs and outputs. Taking it as the basic unit, a N×N DFT device is constructed according to FFT algorithm. We also show the detailed structure and simulation of DFT devices based on Planar Lightwave Circuit (PLC).
Next, this thesis proposes a novel all-optical OFDM system based on the devices mentioned above. The function of each section and operation processes of system are illustrated. A simulation of this all-optical OFDM system at 160Gbit/s is conducted. The results give BER of 7.958×10~(-10) and OSNR of 24.97dB both at receiver. Also performance simulations are implemented, which consist of dispersion character and noise characteristics of different modulation and nonlinear effect in all-optical OFDM system. The feasibility of the system is demonstrated.
OFDM对于无线和铜线的应用,已经是成熟的技术,而在光通信上的应用,却还是比较晚的事。但OFDM的光传输是一个快速发展的研究领域。在非全光OFDM系统中,容量受限于两个主要方面:光数据调制器、光电二极管,和快速傅里叶变换(FFT,Fast Fourier Transform)的电路。而在全光OFDM系统中,FFT以光的方式实现,传输数据率就会大大提高。全光OFDM技术有着很大吸引力,作为以后的大容量、高频谱效率、长距离通信系统的有力候选技术。
本论文首先对OFDM原理在数学上进行了分析,并根据无线应用中OFDM系统的基本功能,讨论了OFDM的关键技术。
然后针对全光OFDM系统,本论文采用了一种基于光耦合器的DFT器件。根据光耦合器的输入输出关系,给它加上适当相移,可以实现两个点的DFT,并作为光DFT基本单元。然后按照FFT算法的思想,用基本单元构造出了N (2的整数次幂)个点的DFT器件。并给出了具体的实现结构和基于平面光路(PLC,Planar Lightwave Circuit)的仿真。
接着提出了基于上述器件的全光OFDM系统,对系统的各个部分及其工作过程做出了细致的说明。对这种全光OFDM系统在160Gbit/s速率下进行了仿真,结果表明接收端的误码率为7.958×10~(-10),接收机前的光信噪比为24.97dB。并进行了性能仿真,主要是分析了不同调制方式下色散和噪声的特性,以及非线性对全光OFDM的影响。
This thesis proposes a novel all-optical Orthogonal Frequency Division Multiplexing (OFDM) transmission system, and studies optical Discrete Fourier Transform (DFT) devices based on optical couplers in this system.
OFDM has been established as a mature technology for applications of wireless and copper, while it is lately applied to optical communication. But optical transmission by OFDM is the fastest growing area in recent years. In not-all-optical OFDM system, the capacity is limited by two major components: the optical data modulator and the photodiode, and electronics for FFT. While in all-optical one, the FFT process is achieved in optical domain, the OFDM transmission data rate can be increased by far. All-optical OFDM becomes an attractive candidate for high capacity, frequency effective, long haul communication systems.
This thesis firstly analyses the mathematical principle of OFDM, and discusses key technologies related to basic functions of wireless OFDM system.
Then, this thesis applies a kind of optical DFT devices based on optical couplers in accordance with all-optical OFDM system. And shows that one coupler can act as a 2×2 DFT device when combined with appropriate phase shift, owing to the relationship between its inputs and outputs. Taking it as the basic unit, a N×N DFT device is constructed according to FFT algorithm. We also show the detailed structure and simulation of DFT devices based on Planar Lightwave Circuit (PLC).
Next, this thesis proposes a novel all-optical OFDM system based on the devices mentioned above. The function of each section and operation processes of system are illustrated. A simulation of this all-optical OFDM system at 160Gbit/s is conducted. The results give BER of 7.958×10~(-10) and OSNR of 24.97dB both at receiver. Also performance simulations are implemented, which consist of dispersion character and noise characteristics of different modulation and nonlinear effect in all-optical OFDM system. The feasibility of the system is demonstrated.
引文
[1]苏福根,金红莉.光复用技术在光通信中的应用.科学之友(B版), 2008, 07: 13~14
[2]原荣.光纤通信技术讲座——(九):光复用技术.光通信技术, 2003, 09: 50~52
[3]李晖. 100 Gbit/s超高速系统的发展及展望.现代电信科技, 2009, 1: 10~14
[4] Winzer P J, Raybon G, Doerr C R, et al. 2000-km WDM Transmission of 10 x 107-Gb/s RZ-DQPSK. in: Proc ECOC, 2006. Th4.1.3
[5] Hiroji M, Akihide S, Takayuki K, et al. 20.4-Tb/s (204 x 111 Gb/s) Transmission over 240 km Using Bandwidth-Maximized Hybrid Raman/EDFAs. in: Proc OFC/NFOEC, 2007. PDP20
[6] C R S Fludger, T Duthel, D van den Borne, et al. 10 x 111 Gbit/s, 50 GHz Spaced, POLMUX-RZ-DQPSK Transmission over 2375 km Employing Coherent Equalisation. in: Proc OFC/NFOEC, 2007. PDP22
[7] Xiang Z, Jianjun Y, Dayou Q, et al. 8 x 114 Gb/s, 25-GHz-Spaced, PolMux-RZ-8PSK Transmission over 640 km of SSMF Employing Digital Coherent Detection and EDFA-Only Amplification. in: Proc OFC/NFOEC, 2008. PDP1
[8] Gabriel C, Jeremie R, Haik M, et al. Transmission of 16.4Tbit/s Capacity over 2,550km Using PDM QPSK Modulation Format and Coherent Receiver. in: Proc OFC/NFOEC, 2008. PDP3
[9]张海懿. 100Gbit/s光传送技术的发展.通信世界, 2008, 12(46): B5~B6
[10] Sander L J, Itsuro M, Hideaki T. 10 x 121.9-Gb/s PDM-OFDM Transmission with 2-b/s/Hz Spectral Efficiency over 1,000 km of SSMF. in: Proc OFC/NFOEC, 2008. PDP2
[11] Qi Y, Yiran M, William S. 107 Gb/s Coherent Optical OFDM Reception Using Orthogonal Band Multiplexing. in: Proc OFC/NFOEC, 2008. PDP7
[12] Yamada E, Sano A, Masuda H, et al. 1Tb/s (111Gb/s/ch x 10ch) No-Guard-Interval CO-OFDM Transmission over 2100 km DSF. in: Proc OECC/ACOFT, 2008. PDP-6
[13] Armstrong J. OFDM: From Copper and Wireless to Optical. in: Proc OFC/NFOEC, 2008. OMM1
[14] Chang R W. Orthogonal Frequency Multiplex Data Transmission System. USA, U.S. Patent 3488445, 1966. 1~35
[15] Salz J, Weinstein S B. Fourier Transform Communication System. in: Proc of the First ACM Symposium on Problems in the Optimization of Data Communications Systems, 1969. 138~149
[16] Peled A, Ruiz A. Frequency Domain Data Transmission Using Teduced Computational Complexity Algorithms. in: Proc ICASSP 1980. Denver: IEEE, 1980. 964~967
[17] Telatar I E. Capacity of Multi-Antenna Gaussian Channels. Technical Memorandum. Bell Laboratories, Lucent Technologies, 1995 (Published in European Transactions on Telecommunications, 1999, 10(6): 585~595
[18] Foschini G J, Gans M J. On Limits of Wireless Communications in a Fading Environment when Using Multiple Antennas. Wireless Personal Communications, 1998, 6(3): 311~335
[19] Cimini L J Jr. Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division Multiplexing. IEEE Transactions on Communications, 1985, 33(7): 665~675
[20] Alard M, Lassalle R. Principles of Modulation and Channel Coding for Digital Broadcasting for Mobile Receivers. EBU Review-Technical, 1987, (224): 168~190
[21] Chow J S, Tu J C, Cioffi J M. A Discrete Multitone Transceiver System for HDSL Applications. IEEE Journal on Selected Areas in Communications, 1991, 9 (6): 895~908
[22] Wilson S K, Armstrong J. Digital Modulation Techniques for Optical Asymmetrically- lipped OFDM. in: Proc IEEE Wireless Communications and Networking Conference, 2008. 538~542
[23] Sano A, Masuda H, Yoshida E, et al. 30 x 100-Gb/s All-Optical OFDM Transmission over 1300 km SMF with 10 ROADM Nodes. in: Proc ECOC, 2007. PD1.7
[24] Lee K, Thai C T D, Rhee JK K. All Optical Discrete Fourier Transform Processor for 100 Gbps OFDM Transmission. Optics Express, 2008, 16(6): 4023~4028
[25]郑君里,应启珩,杨为理.信号与系统. (第二版).北京:高等教育出版社, 2000. 135~138
[26] Tanaka K, Norimatsu S. Transmission Performance of WDM/OFDM Hybrid Systems over Optical Fibers. Electronics and Communications in Japan (Part I: Communications), 2007, 90(10): 14~24
[27] Kahn J M, Barry J R. Wireless Infrared Communications. Proc of the IEEE, 1997, 85(2): 265~298
[28] Carruthers J B, Kahn J M. Multiple-Subcarrier Modulation for Nondirected Wireless Infrared Communication. IEEE Journal on Selected Areas in Communications, 1996, 14(3): 538~546
[29] Gonzalez O, Perez-Jimenez R, Rodriguez S, et al. OFDM over Indoor Wireless Optical Channel. IEE Proc - Optoelectronics, 2005, 152(4): 199~204
[30] Armstrong J, Lowery A J. Power Efficient Optical OFDM. Electronics Letters, 2006, 42(6): 370~372
[31] Armstrong J, Schmidt B J C. Comparison of Asymmetrically Clipped Optical OFDM and DC-Biased Optical OFDM in AWGN. IEEE Communications Letters, 2008, 12(5): 343~345
[32] Schmidt B J C, Lowery A J, Armstrong J. Experimental Demonstrations of Electronic Dispersion Compensation for Long-Haul Transmission Using Direct-Detection Optical OFDM. Journal of Lightwave Technology, 2008, 26(1): 196~203
[33] Lowery A J, Armstrong J. Orthogonal-Frequency-Division Multiplexing for Dispersion Compensation of Long-Haul Optical Systems. Optics Express, 2006, 14(6): 2079~2084
[34] Shieh W, Athaudage C. Coherent Optical Orthogonal Frequency Division Multiplexing. Electronics Letters, 2006, 42(10): 587~588
[35] Greenberg M, Nazarathy M, Orenstein M. Data Parallelization by Optical MIMO Transmission Over Multimode Fiber With Intermodal Coupling. Journal of Lightwave Technology, 2007, 25(6): 1503~1514
[36] Tarighat A, Hsu R C J, Shah A, et al. Fundamentals and Challenges of Optical Multiple-Input Multiple-Output Multimode Fiber Links. IEEE Communications Magazine, 2007, 45(5): 57~63
[37] Lau A P T, Xu L, Wang T. Performance of Receivers and Detection Algorithms for Modal Multiplexing in Multimode Fiber Systems. IEEE Photonics Technology Letters,2007, 19(14): 1087~1089
[38] Shieh W. PMD-Supported Coherent Optical OFDM Systems. IEEE Photonics Technology Letters, 2007, 19(3): 134~136
[39] Jansen S L, Morita I, Tanaka H. 16 x 52.5-Gb/s, 50-GHz Spaced, POLYMUX-CO- OFDM Transmission over 4,160 km of SSMF Enabled by MIMO Processing. in: Proc ECOC, 2007. PD1.3
[40] Ma Y, Shieh W, Yang Q. Bandwidth-Efficient 21.4 Gb/s Coherent Optical 2 x 2 MIMO OFDM Transmission. in: Proc OFC/NFOEC, 2008. JWA59
[41] VPIsystems, Inc. Photonic and Signal Processing Modules Help. with the software VPItransmissionMaker WDM version 7.6, 2007. 1~276
[42]佟学俭,罗涛编著. OFDM移动通信技术原理与应用,北京:人民邮电出版社, 2003. 48~49
[2]原荣.光纤通信技术讲座——(九):光复用技术.光通信技术, 2003, 09: 50~52
[3]李晖. 100 Gbit/s超高速系统的发展及展望.现代电信科技, 2009, 1: 10~14
[4] Winzer P J, Raybon G, Doerr C R, et al. 2000-km WDM Transmission of 10 x 107-Gb/s RZ-DQPSK. in: Proc ECOC, 2006. Th4.1.3
[5] Hiroji M, Akihide S, Takayuki K, et al. 20.4-Tb/s (204 x 111 Gb/s) Transmission over 240 km Using Bandwidth-Maximized Hybrid Raman/EDFAs. in: Proc OFC/NFOEC, 2007. PDP20
[6] C R S Fludger, T Duthel, D van den Borne, et al. 10 x 111 Gbit/s, 50 GHz Spaced, POLMUX-RZ-DQPSK Transmission over 2375 km Employing Coherent Equalisation. in: Proc OFC/NFOEC, 2007. PDP22
[7] Xiang Z, Jianjun Y, Dayou Q, et al. 8 x 114 Gb/s, 25-GHz-Spaced, PolMux-RZ-8PSK Transmission over 640 km of SSMF Employing Digital Coherent Detection and EDFA-Only Amplification. in: Proc OFC/NFOEC, 2008. PDP1
[8] Gabriel C, Jeremie R, Haik M, et al. Transmission of 16.4Tbit/s Capacity over 2,550km Using PDM QPSK Modulation Format and Coherent Receiver. in: Proc OFC/NFOEC, 2008. PDP3
[9]张海懿. 100Gbit/s光传送技术的发展.通信世界, 2008, 12(46): B5~B6
[10] Sander L J, Itsuro M, Hideaki T. 10 x 121.9-Gb/s PDM-OFDM Transmission with 2-b/s/Hz Spectral Efficiency over 1,000 km of SSMF. in: Proc OFC/NFOEC, 2008. PDP2
[11] Qi Y, Yiran M, William S. 107 Gb/s Coherent Optical OFDM Reception Using Orthogonal Band Multiplexing. in: Proc OFC/NFOEC, 2008. PDP7
[12] Yamada E, Sano A, Masuda H, et al. 1Tb/s (111Gb/s/ch x 10ch) No-Guard-Interval CO-OFDM Transmission over 2100 km DSF. in: Proc OECC/ACOFT, 2008. PDP-6
[13] Armstrong J. OFDM: From Copper and Wireless to Optical. in: Proc OFC/NFOEC, 2008. OMM1
[14] Chang R W. Orthogonal Frequency Multiplex Data Transmission System. USA, U.S. Patent 3488445, 1966. 1~35
[15] Salz J, Weinstein S B. Fourier Transform Communication System. in: Proc of the First ACM Symposium on Problems in the Optimization of Data Communications Systems, 1969. 138~149
[16] Peled A, Ruiz A. Frequency Domain Data Transmission Using Teduced Computational Complexity Algorithms. in: Proc ICASSP 1980. Denver: IEEE, 1980. 964~967
[17] Telatar I E. Capacity of Multi-Antenna Gaussian Channels. Technical Memorandum. Bell Laboratories, Lucent Technologies, 1995 (Published in European Transactions on Telecommunications, 1999, 10(6): 585~595
[18] Foschini G J, Gans M J. On Limits of Wireless Communications in a Fading Environment when Using Multiple Antennas. Wireless Personal Communications, 1998, 6(3): 311~335
[19] Cimini L J Jr. Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division Multiplexing. IEEE Transactions on Communications, 1985, 33(7): 665~675
[20] Alard M, Lassalle R. Principles of Modulation and Channel Coding for Digital Broadcasting for Mobile Receivers. EBU Review-Technical, 1987, (224): 168~190
[21] Chow J S, Tu J C, Cioffi J M. A Discrete Multitone Transceiver System for HDSL Applications. IEEE Journal on Selected Areas in Communications, 1991, 9 (6): 895~908
[22] Wilson S K, Armstrong J. Digital Modulation Techniques for Optical Asymmetrically- lipped OFDM. in: Proc IEEE Wireless Communications and Networking Conference, 2008. 538~542
[23] Sano A, Masuda H, Yoshida E, et al. 30 x 100-Gb/s All-Optical OFDM Transmission over 1300 km SMF with 10 ROADM Nodes. in: Proc ECOC, 2007. PD1.7
[24] Lee K, Thai C T D, Rhee JK K. All Optical Discrete Fourier Transform Processor for 100 Gbps OFDM Transmission. Optics Express, 2008, 16(6): 4023~4028
[25]郑君里,应启珩,杨为理.信号与系统. (第二版).北京:高等教育出版社, 2000. 135~138
[26] Tanaka K, Norimatsu S. Transmission Performance of WDM/OFDM Hybrid Systems over Optical Fibers. Electronics and Communications in Japan (Part I: Communications), 2007, 90(10): 14~24
[27] Kahn J M, Barry J R. Wireless Infrared Communications. Proc of the IEEE, 1997, 85(2): 265~298
[28] Carruthers J B, Kahn J M. Multiple-Subcarrier Modulation for Nondirected Wireless Infrared Communication. IEEE Journal on Selected Areas in Communications, 1996, 14(3): 538~546
[29] Gonzalez O, Perez-Jimenez R, Rodriguez S, et al. OFDM over Indoor Wireless Optical Channel. IEE Proc - Optoelectronics, 2005, 152(4): 199~204
[30] Armstrong J, Lowery A J. Power Efficient Optical OFDM. Electronics Letters, 2006, 42(6): 370~372
[31] Armstrong J, Schmidt B J C. Comparison of Asymmetrically Clipped Optical OFDM and DC-Biased Optical OFDM in AWGN. IEEE Communications Letters, 2008, 12(5): 343~345
[32] Schmidt B J C, Lowery A J, Armstrong J. Experimental Demonstrations of Electronic Dispersion Compensation for Long-Haul Transmission Using Direct-Detection Optical OFDM. Journal of Lightwave Technology, 2008, 26(1): 196~203
[33] Lowery A J, Armstrong J. Orthogonal-Frequency-Division Multiplexing for Dispersion Compensation of Long-Haul Optical Systems. Optics Express, 2006, 14(6): 2079~2084
[34] Shieh W, Athaudage C. Coherent Optical Orthogonal Frequency Division Multiplexing. Electronics Letters, 2006, 42(10): 587~588
[35] Greenberg M, Nazarathy M, Orenstein M. Data Parallelization by Optical MIMO Transmission Over Multimode Fiber With Intermodal Coupling. Journal of Lightwave Technology, 2007, 25(6): 1503~1514
[36] Tarighat A, Hsu R C J, Shah A, et al. Fundamentals and Challenges of Optical Multiple-Input Multiple-Output Multimode Fiber Links. IEEE Communications Magazine, 2007, 45(5): 57~63
[37] Lau A P T, Xu L, Wang T. Performance of Receivers and Detection Algorithms for Modal Multiplexing in Multimode Fiber Systems. IEEE Photonics Technology Letters,2007, 19(14): 1087~1089
[38] Shieh W. PMD-Supported Coherent Optical OFDM Systems. IEEE Photonics Technology Letters, 2007, 19(3): 134~136
[39] Jansen S L, Morita I, Tanaka H. 16 x 52.5-Gb/s, 50-GHz Spaced, POLYMUX-CO- OFDM Transmission over 4,160 km of SSMF Enabled by MIMO Processing. in: Proc ECOC, 2007. PD1.3
[40] Ma Y, Shieh W, Yang Q. Bandwidth-Efficient 21.4 Gb/s Coherent Optical 2 x 2 MIMO OFDM Transmission. in: Proc OFC/NFOEC, 2008. JWA59
[41] VPIsystems, Inc. Photonic and Signal Processing Modules Help. with the software VPItransmissionMaker WDM version 7.6, 2007. 1~276
[42]佟学俭,罗涛编著. OFDM移动通信技术原理与应用,北京:人民邮电出版社, 2003. 48~49