Optical Fiber Communication System Simulation and Common Communication Interface TechnologyAbstractThis paper describes the development direction of optical fiber communications, described the characteristics of system simulation and development at home and abroad. The second part is commonly used by communication interface interface discussion.Keywords Opticalfibercommunications,development,SystemSimulation,Interface 1 Outline1.1 Optical Fiber CommunicationIn the "information superhighway" concept was put forward after the optical fiber communication technology in increasing the capacity and extend the communication distance has made rapid development. Broadband fiber amplifier W-EDFA (Wide band Erbium-Doped Fiber Amplifier) and dense wavelength division multiplexing optical fiber communication technology development is the most eye-catching direction. Loss and dispersion in order to reduce the design of the dispersion shifted fiber DSF (Dispersion Shifted Fiber), in the 1525-1565nm band, the dispersion fell to -2 - +3 ps / (nm • km) between; zero dispersion at 1540nm. DWDM systems to reduce four-wave mixing effect, but also designed a new type of non-zero dispersion fiber NZDF (Non-Zero Dispersion Fiber). At the same time, integrated opto-electronics technologies (OEIC) is the rapid development of vertical-cavity surface-emitting laser VCSEL (Vertical Ca-vity Surface Emitting Laser) and electro-optical receiver optoelectronic integration has been achieved. Around a variety of light (OTDM) At present, there are active in research units.1.2 System SimulationSystem simulation is developed in the last two decades a science and emerging technologies. Is the so-called computer simulation model on the computer system forexperimental study of the actual process. The use of computer simulation can be repeated simulation of the same phenomenon of the objective world and thus to find out the inherent laws. In particular, contain random variables and random process, it is difficult to establish a mathematical model of an objective study of things, the computer simulation method has obvious advantages, has become the analysis, research and design of an important means of various systems. The application of computer simulation technology to the field of communications is one of an important branch. With the development of communication technologies, communications networks, the number and complexity of the rapid growth of the design of communication systems in use of computer simulation technology has become a new system designed to shorten the design cycle and improve design reliability and improved system performance has been an indispensable tool.2 Optical fiber communication system simulationOptical fiber communication technology is more than one cross-discipline integrated technology penetration. It involves the basic theory of communication (such as digital communication technology), and microwave technologies (such as fiber channel analysis of electromagnetic fields), as well as circuit design and microelectronic technology (such as application specific integrated circuit ASIC) and so on. Therefore, whether it is systematic planning and design, or a new type of transmission system and the system of exploration and research, have experienced lengthy complicated calculations. In addition, in order to verify whether the performance requirements of Section need to research and experiment repeated testing. If every time the direct use of the real system experiments, not only the cost of expensive, labor-and time-consuming and sometimes difficult to find the crux of the problem, therefore, address these problems is an effective means of computer simulation techniques, namely through the establishment of device components and the system model , and model experiments on the computer, using high-speed computer processing capacity, completion of the fiber-optic communicationsequipment and systems analysis, design optimization and performance testing and evaluation.2.1 Optical fiber communication system simulation software, the status quoThe simulation is divided into circuit simulation and system-level simulation. Circuit-level simulation by resistors, capacitors, inductors and other components of the circuit model equivalent to the outer characteristics of Analog Devices. System-level simulation is Rong transfer function or the number of formula characteristics of analog simulation. Abroad, some optical fiber communication system simulation software for circuit analysis, focusing on different, such as the Boss is a user-friendly optical link simulation software, which includes fiber-optic device model, but only in a single wavelength system. SCOPE (Super Co-mpact Optoelectronic Simulation) is a kind of the photovoltaic devices and optical devices using the two-port network model to simulate the nonlinear microwave simulation software, its main use is in the microwave frequency of IM / DD Optical Communication Systems simulation. DEX SOLUS (Simulation of Light Using Spice) is based on the Spice circuit simulation software dedicated to the field of optical communication signal analysis software, it uses the equivalent circuit model to simulate optoelectronic devices, optical power of the models used in the simulation of voltage to represent . There are other circuit-level simulation software such as iSMILE and MISIM. IBM's OLAP (Optical Link Analysis Program) is a low-level to SYSTID and simulation software of optical devices integrated with software applications. There are a number of new simulation software, such as iFROST (illinois FibeR-optic and Optoelectronic Systems Toolkit), etc., the user can call other simulation software to provide a mixed-level simulation environment.3 Common Communication Interface T echnology3.1 Converters in parallel with the string attached to optoelectronic devicesIn high-speed optical fiber communication systems, transmission of data stream format conversion is required, that is, at the time of optical transmission in serial form and in electronic format when theparallel between the conversion. Serializer -deserializer (generally known as the Serial and Parallel converter) is used to achieve this conversion. Serial and Parallel converter and the interface between the photoelectric sensor is usually high-speed serial data stream, using a different coding schemes signaling, this can be embedded clock data recovery. According to the communication standards supported by the serial stream can be 1.25Gb / s (Gigabit Ethernet), 2.488Gb / s (OC-48/STM-16), 9.953Gb / s (OC-192/STM- 64) or 10.3Gb / s (10 Gigabit Ethernet) transmission conditions.3.2 Serial and Parallel interface converter to the framersIn the Sonet / SDH in the world, fiber optic data transmission is often in the form of the use of frames. Each frame, including additional information (for synchronization, error monitoring, protection switching, etc.) and payload data. Transmission equipment must be added to output data in the frame of the additional information, the receiving device must be extracted from the frame payload data, and additional information frame systems management. These operations will be completed in the framersAs the framers of the need to achieve some complex digital logic, which determines the parallel series converter used with the framers of the interface between technology and the use of standard CMOS technology to create a high level of integration of the IC. The current CMOS technology can not support the 10Gb / s serial data stream, the parallel series converter and the need for parallel interface between framers. At present, the most popular choice is the Internet forum by the Optical Network (Optical Internetworking Forum) to develop the SFI-4, the interface speeds of up to two 622Mb / s 16-bit parallel data streams (one in each direction). SFI-4 and as many new interfaces, the use of source-synchronous clock, the clock signal and data that is shared by the transmission signal transmission devices. Source-synchronous clock can significantly reduce the clock signal and data signals between the offset, but it can not completely eliminate the line length does not match the PCB-induced migration effects. 16 data signals and clock signal are the use of IEEE-1593.6 standard LVDS signaling. The parallel interface only in the seriesconverter and transmit data back and forth between framers, shorter distance, there is no need to have a complex flow control or error detection.3.3 Control panel interfaceMotorola has been and Rapid IO Trade Association supported the use of Rapid IO switch architecture to achieve point-to-point link interface. The interface provides the data transport layer to package in the package, each packet has a data source and target information, the packet switch architecture will be sent to the appropriate destination. Rapid IO in each direction to provide 8 or 16-bit, 250MHz ~ 1.0GHz using Double Data Rate. In addition, Serial Rapid IO can be used with 8b/10b encoding a channel or 4-channel data, embedded clock of 3.125Gb / s, it has a differential CML signaling.AMD and the development of Hyper Transport Union Hyper Transport channel devices using point-to-point link. The form of data packet transmission, each packet includes a data source and target information. Access device to receive data in accordance with the packet header to determine the data transmitted to the next in the chain of devices, or deal directly with the data. Hyper Transport current norms for the needs of the width of 2 ~ 16-bit parallel data. Norms to support the next higher rate. PMC-Sierra and Bro AD Com has been the introduction of Hyper Transport communications products based on the MIPS processor.PCI-SIG has introduced high-speed PCI-X. They use the PCI-X same as the original 64-bit bus bandwidth to support double-data rate and four times the data rate. PCI-X 533 version is the fastest rate, maximum total bandwidth of 34.1Gb / s.PCI-X communication protocol of the transmission signal and the standard connector format in conjunction with the PCI-compatible, enabling 3.3V 32-bit PCI adapter card can be used in PCI-X expansion slots on. Of course, if you prefer, you can be 64-bit PCI-X adapter card access in the 32-bit PCI expansion slots, but bandwidth will be greatly reduced speed.4 ConclusionAt present, China's optical fiber communication system simulation study has beenstarted, such as Tsinghua University, Tianjin University, etc. some success, to design a highly functional and reliable performance of the optical fiber communication system simulation package, to adapt to the rapid development of optical fiber communications have important theoretical and practical significance, has a high cost-effective and broad application prospects.光纤通信系统仿真及常用通信接口技术摘要介绍了光纤通信的发展方向，阐述了系统仿真的特点及国内外的发展状况，第二部分为现用通信接口中常用接口讨论。