嵌入式系统在光纤测量中的应用研究
摘要
随着信息时代的到来,传统的通过电缆传递信息的方式已不能满足需要。光纤损耗低、带宽宽、容量大、原材料丰富,从各方面讲都是替代传统电缆的最好选择,所以国内对光纤检测仪器的需求很大。目前,光纤检测仪,即光时域反射仪,主要依赖于进口,这非常不利于我国知识产权的自主化,所以亟需开发一种低成本、测量准确、适合工程应用的光时域反射仪。
本论文首先介绍了光纤测量技术的现状并给出了光时域反射仪的基本光学原理和基本工作原理,在此基础上提出使用嵌入式系统是实现此功能的最好选择;接下来详细介绍了我所搭建的数字平台,从功能、开发难度和成本几方面综合考虑最终确立了以DSP为中心主控芯片,FLASH、SDRAM和CPLD为外围功能模块的总体方案;而后介绍如何根据BOXcar原理编写程序完成系统功能,最后给出系统调试方法,包括硬件调试和软件调试以及在实际应用中积累的一些经验。
文章深入探讨了ADI公司的ADSP-BF531的功能和开发过程,同时提出一种在功能和速度上都能很好满足系统需要的一种算法:BOXcar算法,并给出算法框图。ADSP-BF531是ADI公司新一代16位高速DSP产品,这一新产品是专为通信和互联网应用而设计的通用DSP芯片,能处理广泛用于互联网的大量图像、声音、文本和数据流,适用于电信和各种互联网设备。BOXcar算法是基于硬件BOXcar提出的一种改良算法,克服了硬件实现时离散性大,设备复杂等缺点,它的核心概念是积累平均。
经过实际验证,证明该系统能够根据国际标准完成对光纤的衰减和长度等指标的检测且测量准确迅速,可以达到国外先进水平。
Nowadays, our country’s information industry is developing at a phenomenal rate, through the traditional media to transfer the information have failed to meet the increased needs. The optical fiber as a new carrier has many merits, such as the lower spoilage, broader band width, larger capacity and the enough material, so it is the best choice to replace the traditional carrier. At present, the main device to detect the optical fiber is Optical Time Domain Reflector. Because in the project it is essential, so the demand is very big in our country, but the majority of instruments rely on in import. So it is not advantageous to the independence of our country’s intellectual property rights. Therefore we must develop one kind of low cost, suitable project application OTDR.
Firstly, this paper introduce the present situation of the optical fiber examination technology and the basic optics principle and basic principle of work, in this foundation, proposing the embedded system is the best choice to realize this function. The embedded system is a popular research area, it widely applies in the electron, the medical service, the aviation and the automobile industry. Nest I introduce the digital platform, on this basis, I raised the main chip is ADSP-BF531, and the peripheral chips are FLASH、SDRAM and CPLD. After that, I introduced how to program according to the BOXcar principle. Last, I introduced the methods of system debugging.
Mainly, I emphasized the function of main chip ADSP-BF531 and the main algorithm: BOXcar algorithm. ADSP-BF531 is ADI corporation’s new generation of high speed DSP product, this new product is designed for the communication and internet applications, and it can process the massive images, the sound, the text and data stream. The BOXcar algorithm is a kind of improvement algorithm, which based on the BOXcar device, it overcome a lot of shortcoming of the device.
The experiments prove that this system can test the attenuation and the length of the optical fiber accurately according to the international standard.
本论文首先介绍了光纤测量技术的现状并给出了光时域反射仪的基本光学原理和基本工作原理,在此基础上提出使用嵌入式系统是实现此功能的最好选择;接下来详细介绍了我所搭建的数字平台,从功能、开发难度和成本几方面综合考虑最终确立了以DSP为中心主控芯片,FLASH、SDRAM和CPLD为外围功能模块的总体方案;而后介绍如何根据BOXcar原理编写程序完成系统功能,最后给出系统调试方法,包括硬件调试和软件调试以及在实际应用中积累的一些经验。
文章深入探讨了ADI公司的ADSP-BF531的功能和开发过程,同时提出一种在功能和速度上都能很好满足系统需要的一种算法:BOXcar算法,并给出算法框图。ADSP-BF531是ADI公司新一代16位高速DSP产品,这一新产品是专为通信和互联网应用而设计的通用DSP芯片,能处理广泛用于互联网的大量图像、声音、文本和数据流,适用于电信和各种互联网设备。BOXcar算法是基于硬件BOXcar提出的一种改良算法,克服了硬件实现时离散性大,设备复杂等缺点,它的核心概念是积累平均。
经过实际验证,证明该系统能够根据国际标准完成对光纤的衰减和长度等指标的检测且测量准确迅速,可以达到国外先进水平。
Nowadays, our country’s information industry is developing at a phenomenal rate, through the traditional media to transfer the information have failed to meet the increased needs. The optical fiber as a new carrier has many merits, such as the lower spoilage, broader band width, larger capacity and the enough material, so it is the best choice to replace the traditional carrier. At present, the main device to detect the optical fiber is Optical Time Domain Reflector. Because in the project it is essential, so the demand is very big in our country, but the majority of instruments rely on in import. So it is not advantageous to the independence of our country’s intellectual property rights. Therefore we must develop one kind of low cost, suitable project application OTDR.
Firstly, this paper introduce the present situation of the optical fiber examination technology and the basic optics principle and basic principle of work, in this foundation, proposing the embedded system is the best choice to realize this function. The embedded system is a popular research area, it widely applies in the electron, the medical service, the aviation and the automobile industry. Nest I introduce the digital platform, on this basis, I raised the main chip is ADSP-BF531, and the peripheral chips are FLASH、SDRAM and CPLD. After that, I introduced how to program according to the BOXcar principle. Last, I introduced the methods of system debugging.
Mainly, I emphasized the function of main chip ADSP-BF531 and the main algorithm: BOXcar algorithm. ADSP-BF531 is ADI corporation’s new generation of high speed DSP product, this new product is designed for the communication and internet applications, and it can process the massive images, the sound, the text and data stream. The BOXcar algorithm is a kind of improvement algorithm, which based on the BOXcar device, it overcome a lot of shortcoming of the device.
The experiments prove that this system can test the attenuation and the length of the optical fiber accurately according to the international standard.
引文
[1] 顾畹以,李国瑞,光纤通信系统,北京:邮电大学出版社,2002
[2] 曲林杰,廖延彪,李昱,张庆瑞,物理光学,国防工业出版社,1995
[3] ADSP-BF53x Blackfin Processor Hardware Reference,Analog Device,2003
[4] SST39VF020 Data Manual,Silicon Storage Technology,1999
[5] IS42S16800A Data Manual,Integrated Silicon Solution,2003
[6] 赵继勇,彭飞,高速ADC的低抖动时钟设计,电子设计应用,2005(2)
[7] 陈尚松,雷加,郭庆,电子测量与仪器,北京:电子工业出版社,2005
[8] 徐科军,黄云志,定点 DSP 的原理、开发与应用,北京:清华大学出版社,2002
[9] Ohashi. M, Novel OTDR Technique for Measuring Relative-Index Differences of Fiber Links. Photonics Technology Letters, IEEE, Volume 18, Issue 24, Dec.15, 2006 Page(s):2584 – 2586.
[10] ADSP-BF53x Data Manual,Analog Device,2005
[11] 廖延彪,偏振光学,科学出版社,2003
[12] J. Gower. Optical Communication System. 1983
[13] Jean J. L labrosse.嵌入式实时操作系统μC/OS-Ⅱ,北京:北京航空航天大学出版社,2004.
[14] 王念旭。DSP基础与应用系统设计,北京:北京航空航天大学出版社,2001.
[15] Duckey Lee; Hosung Yoon; Pilhan Kim; Jonghan Park; SNR enhancement of OTDR using biorthogonal codes and generalized inverses. Photonics Technology Letters, IEEE Volume 17, Issue 1, Jan. 2005
[16] 宋万杰,罗杰,吴顺君.CPLD技术及其应用.西安:西安电子科技大学出版社,1999.
[17] 彭志刚,董金明.CPLD在DSP设计中的应用.电子测量技术,2001(1):25-26.
[18] Smith. M ; Roland. D,Understanding differences between OTDR and cut-back attenuation measurements in multimode graded index fiber. Lasers and Electro-Optics Society Annual Meeting, 1996. LEOS 96., IEEE.
[19] 陈峰,Blackfin系列DSP原理与系统设计,北京:电子工业出版社,2004
[20] Taeyeon Lee; Ealgoo Kim; Jaehong Park; A method of a repetitive sampling measurement for OTDR considering a ghost effect to a short-range measurement witha short-length fiber. Nuclear Science Symposium Conference Record, 2005 IEEE.
[21] 李真芳,苏涛.DSP程序开发-MATLAB调试及目标代码生成,西安:西安电子科技大学出版社,2003
[22] 李强.采用OTDR准确判断光缆线路故障点.华北电力技术,2005增刊.
[23] 周晔,郑正奇,杨勇. 基于DSP的数据采集和频谱分析系统.信息与通信技术,2006(4).
[24] Hongxin Chen; Leblanc, M. Reduction of the impairment of online OTDR monitoring by use of a narrow bandwidth OTDR and an optical bandpass filter. Photonics Technology Letters, IEEE Volume 16, Issue 9, Sept. 2004
[25] Duckey Lee; Hosung Yoon; Pilhan Kim; Optimization of SNR improvement in the noncoherent OTDR based on simplex codes. Lightwave Technology, Journal of Volume 24, Issue 1, Jan. 2006
[26] Duckey Lee; Hosung Yoon; Na Young Kim. Analysis and experimental demonstration of simplex coding technique for SNR enhancement of OTDR. Lightwave Technologies in Instrumentation and Measurement Conference, 2004. Proceedings of the 19-20 Oct. 2004 Page(s):118 – 122
[27] Ozeki, T.; Seki, S.; Iwasaki, K. PMD Distribution Measurement by an OTDR With Polarimetry Considering Depolarization of Backscattered Waves. Lightwave Technology, Journal of Volume 24, Issue 11, Nov. 2006 Page(s):3882 – 3888.
[28] Lee, H.H.; Nam, Y.H.; Lee, D. Demonstration of a low-cost 1625-nm OTDR monitoring for 350-km WDM networks with semiconductor optical amplifiers. Photonics Technology Letters, IEEE Volume 17, Issue 4, April 2005 Page(s):852 – 854.
[29] Szu-Chi Tsai; Ming-Hong Huang; Yung-Kuang Chen. Stimulated Raman scattering-induced baseband video distortion due to 1.65-/spl mu/m OTDR online monitoring in 1.55-/spl mu/m AM-VSB CATV system. Photonics Technology Letters, IEEE Volume 14, Issue 7, July 2002 Page(s):1016 – 1018.
[30] Juarez, J.C.; Maier, E.W.; Kyoo Nam Choi. Distributed fiber-optic intrusion sensor system. Lightwave Technology, Journal of Volume 23, Issue 6, June 2005 Page(s):2081 – 2087.
[31] Zanobini, A.; Iuculano, G.; Ponterio, A. Distance scale calibration of optical time-domain reflectometers with the recirculating delay line method. Instrumentation and Measurement, IEEE Transactions on Volume 54, Issue 6, Dec. 2005 Page(s):2554 – 2556.
[32] Fenglei Liu; Zarowski, C.J. Detection and location of connection splice events in fiber optics given noisy OTDR data. Part II. R1MSDE method. Instrumentation and Measurement, IEEE Transactions on Volume 53, Issue 2, April 2004 Page(s):546 – 556.
[33] Keeler, G.A.; Serkland, D.K.; Geib, K.M. In situ OTDR for low-cost optical networks using singlemode 850 nm VCSEL. Electronics Letters Volume 41, Issue 14, 7 July 2005 Page(s):819 – 820.
[34] Kawakami, H.; Masuda, H.; Miyamoto, Y. Directional bypass configuration in remotely-pumped EDF/distributed Raman hybrid amplifier scheme for online OTDR monitoring. Electronics Letters Volume 40, Issue 4, Feb 2004 Page(s):259 – 260.
[35] Mai, T.V.; Molnar, J.A.; Tran, L.H. Fiber optic test equipment - evaluation of OTDR dead zones and ORLM return loss. AUTOTESTCON 2004. Proceedings 20-23 Sept. 2004 Page(s):94 – 98.
[36] Inoue, Y.; Aiba, T.; Shibata, N. Measuring modal birefringence along a holey fiber by photon-counting OTDR. Photonics Technology Letters, IEEE Volume 17, Issue 6, June 2005 Page(s):1238 – 1240.
[37] Wuilpart, M.; Ravet, G.; Megret, P. Distributed measurement of Raman gain spectrum in concatenations of optical fibres with OTDR. Electronics Letters Volume 39, Issue 1, 9 Jan 2003 Page(s):88 – 89.
[38] Adachi, S.; Koyamada, Y. Analysis and design of Q-switched erbium-doped fiber lasers and their application to OTDR. Lightwave Technology, Journal of Volume 20, Issue 8, Aug. 2002 Page(s):1506 – 1511.
[39] Araki, N.; Izumita, H.; Honda, N. Extended optical fiber line testing system using new eight-channel L/U-band crossed optical waveguide coupler for L-band WDM transmission. Lightwave Technology, Journal of Volume 21, Issue 12, Dec. 2003 Page(s):3316 – 3322.
[40] Galtarossa, A.; Palmieri, L. Spatially resolved PMD measurements. Lightwave Technology, Journal of Volume 22, Issue 4, April 2004 Page(s):1103 – 1115.
[41] Keeler, G.A.; Serkland, D.K.; Geib, K.M. In-situ OTDR measurements for single-mode optical networks with a standard VCSEL. Lasers and Electro-Optics Society, 2004. LEOS 2004. The 17th Annual Meeting of the IEEE Volume 2, 7-11 Nov. 2004 Page(s):681 - 682 Vol.2.
[2] 曲林杰,廖延彪,李昱,张庆瑞,物理光学,国防工业出版社,1995
[3] ADSP-BF53x Blackfin Processor Hardware Reference,Analog Device,2003
[4] SST39VF020 Data Manual,Silicon Storage Technology,1999
[5] IS42S16800A Data Manual,Integrated Silicon Solution,2003
[6] 赵继勇,彭飞,高速ADC的低抖动时钟设计,电子设计应用,2005(2)
[7] 陈尚松,雷加,郭庆,电子测量与仪器,北京:电子工业出版社,2005
[8] 徐科军,黄云志,定点 DSP 的原理、开发与应用,北京:清华大学出版社,2002
[9] Ohashi. M, Novel OTDR Technique for Measuring Relative-Index Differences of Fiber Links. Photonics Technology Letters, IEEE, Volume 18, Issue 24, Dec.15, 2006 Page(s):2584 – 2586.
[10] ADSP-BF53x Data Manual,Analog Device,2005
[11] 廖延彪,偏振光学,科学出版社,2003
[12] J. Gower. Optical Communication System. 1983
[13] Jean J. L labrosse.嵌入式实时操作系统μC/OS-Ⅱ,北京:北京航空航天大学出版社,2004.
[14] 王念旭。DSP基础与应用系统设计,北京:北京航空航天大学出版社,2001.
[15] Duckey Lee; Hosung Yoon; Pilhan Kim; Jonghan Park; SNR enhancement of OTDR using biorthogonal codes and generalized inverses. Photonics Technology Letters, IEEE Volume 17, Issue 1, Jan. 2005
[16] 宋万杰,罗杰,吴顺君.CPLD技术及其应用.西安:西安电子科技大学出版社,1999.
[17] 彭志刚,董金明.CPLD在DSP设计中的应用.电子测量技术,2001(1):25-26.
[18] Smith. M ; Roland. D,Understanding differences between OTDR and cut-back attenuation measurements in multimode graded index fiber. Lasers and Electro-Optics Society Annual Meeting, 1996. LEOS 96., IEEE.
[19] 陈峰,Blackfin系列DSP原理与系统设计,北京:电子工业出版社,2004
[20] Taeyeon Lee; Ealgoo Kim; Jaehong Park; A method of a repetitive sampling measurement for OTDR considering a ghost effect to a short-range measurement witha short-length fiber. Nuclear Science Symposium Conference Record, 2005 IEEE.
[21] 李真芳,苏涛.DSP程序开发-MATLAB调试及目标代码生成,西安:西安电子科技大学出版社,2003
[22] 李强.采用OTDR准确判断光缆线路故障点.华北电力技术,2005增刊.
[23] 周晔,郑正奇,杨勇. 基于DSP的数据采集和频谱分析系统.信息与通信技术,2006(4).
[24] Hongxin Chen; Leblanc, M. Reduction of the impairment of online OTDR monitoring by use of a narrow bandwidth OTDR and an optical bandpass filter. Photonics Technology Letters, IEEE Volume 16, Issue 9, Sept. 2004
[25] Duckey Lee; Hosung Yoon; Pilhan Kim; Optimization of SNR improvement in the noncoherent OTDR based on simplex codes. Lightwave Technology, Journal of Volume 24, Issue 1, Jan. 2006
[26] Duckey Lee; Hosung Yoon; Na Young Kim. Analysis and experimental demonstration of simplex coding technique for SNR enhancement of OTDR. Lightwave Technologies in Instrumentation and Measurement Conference, 2004. Proceedings of the 19-20 Oct. 2004 Page(s):118 – 122
[27] Ozeki, T.; Seki, S.; Iwasaki, K. PMD Distribution Measurement by an OTDR With Polarimetry Considering Depolarization of Backscattered Waves. Lightwave Technology, Journal of Volume 24, Issue 11, Nov. 2006 Page(s):3882 – 3888.
[28] Lee, H.H.; Nam, Y.H.; Lee, D. Demonstration of a low-cost 1625-nm OTDR monitoring for 350-km WDM networks with semiconductor optical amplifiers. Photonics Technology Letters, IEEE Volume 17, Issue 4, April 2005 Page(s):852 – 854.
[29] Szu-Chi Tsai; Ming-Hong Huang; Yung-Kuang Chen. Stimulated Raman scattering-induced baseband video distortion due to 1.65-/spl mu/m OTDR online monitoring in 1.55-/spl mu/m AM-VSB CATV system. Photonics Technology Letters, IEEE Volume 14, Issue 7, July 2002 Page(s):1016 – 1018.
[30] Juarez, J.C.; Maier, E.W.; Kyoo Nam Choi. Distributed fiber-optic intrusion sensor system. Lightwave Technology, Journal of Volume 23, Issue 6, June 2005 Page(s):2081 – 2087.
[31] Zanobini, A.; Iuculano, G.; Ponterio, A. Distance scale calibration of optical time-domain reflectometers with the recirculating delay line method. Instrumentation and Measurement, IEEE Transactions on Volume 54, Issue 6, Dec. 2005 Page(s):2554 – 2556.
[32] Fenglei Liu; Zarowski, C.J. Detection and location of connection splice events in fiber optics given noisy OTDR data. Part II. R1MSDE method. Instrumentation and Measurement, IEEE Transactions on Volume 53, Issue 2, April 2004 Page(s):546 – 556.
[33] Keeler, G.A.; Serkland, D.K.; Geib, K.M. In situ OTDR for low-cost optical networks using singlemode 850 nm VCSEL. Electronics Letters Volume 41, Issue 14, 7 July 2005 Page(s):819 – 820.
[34] Kawakami, H.; Masuda, H.; Miyamoto, Y. Directional bypass configuration in remotely-pumped EDF/distributed Raman hybrid amplifier scheme for online OTDR monitoring. Electronics Letters Volume 40, Issue 4, Feb 2004 Page(s):259 – 260.
[35] Mai, T.V.; Molnar, J.A.; Tran, L.H. Fiber optic test equipment - evaluation of OTDR dead zones and ORLM return loss. AUTOTESTCON 2004. Proceedings 20-23 Sept. 2004 Page(s):94 – 98.
[36] Inoue, Y.; Aiba, T.; Shibata, N. Measuring modal birefringence along a holey fiber by photon-counting OTDR. Photonics Technology Letters, IEEE Volume 17, Issue 6, June 2005 Page(s):1238 – 1240.
[37] Wuilpart, M.; Ravet, G.; Megret, P. Distributed measurement of Raman gain spectrum in concatenations of optical fibres with OTDR. Electronics Letters Volume 39, Issue 1, 9 Jan 2003 Page(s):88 – 89.
[38] Adachi, S.; Koyamada, Y. Analysis and design of Q-switched erbium-doped fiber lasers and their application to OTDR. Lightwave Technology, Journal of Volume 20, Issue 8, Aug. 2002 Page(s):1506 – 1511.
[39] Araki, N.; Izumita, H.; Honda, N. Extended optical fiber line testing system using new eight-channel L/U-band crossed optical waveguide coupler for L-band WDM transmission. Lightwave Technology, Journal of Volume 21, Issue 12, Dec. 2003 Page(s):3316 – 3322.
[40] Galtarossa, A.; Palmieri, L. Spatially resolved PMD measurements. Lightwave Technology, Journal of Volume 22, Issue 4, April 2004 Page(s):1103 – 1115.
[41] Keeler, G.A.; Serkland, D.K.; Geib, K.M. In-situ OTDR measurements for single-mode optical networks with a standard VCSEL. Lasers and Electro-Optics Society, 2004. LEOS 2004. The 17th Annual Meeting of the IEEE Volume 2, 7-11 Nov. 2004 Page(s):681 - 682 Vol.2.