【作者】 葛凌志；

【导师】 肖石林；

【作者基本信息】 上海交通大学 ， 通信与信息系统， 2010， 硕士

【摘要】 随着视频点播、高清电视、网络电话(VoIP)等业务的迅速发展,人们对宽带接入网的要求越来越高,而传统的数字用户线(xDSL)接入方式不能满足这些新型业务的需求,迫切需要新的技术来解决这个问题。因此,无源光网络(PON)成为当前的研究热点,其中时分复用无源光网络(TDM-PON)技术已经得到了商用。但是TDM-PON采用时分复用接入方式,多个用户共享带宽资源,这样一个用户得到的带宽也很有限,不能适应未来高带宽多业务的需求。并且,由于TDM-PON需要对时隙严格控制,这样带来了管理上的复杂度。于是,波分复用无源光网络(WDM-PON)成为了下一代光纤宽带接入网的主要方案之一。本文主要围绕WDM-PON中载波重用和组播传输技术展开系统的研究。首先介绍了接入网的基础知识,分析了WDM-PON系统构架,明确了本研究工作的意义。然后系统仿真研究了WDM-PON中上行载波重调制技术,对采用强度调制格式的方案进行了深入研究,给出了最佳性能点,为实现低成本、“无色化”的光网络单元(ONU)提供了很好的理论参考方案,具有很好的指导价值。其次,在无源光网络中,随着用户业务的不断增加,组播/广播也是急需解决的问题。本文中在分析了现有组播方案的基础上,提出了基于NRZ/Manchester码型动态切换的组播方案,通过动态的切换开关来选择下行单播数据采用的调制格式,进而实现组播技术。该方案能够灵活的实现组播/广播业务,并且具有实现简单、时钟易恢复等优点。为了进一步提高光网络中节点的高速数据处理能力,本文对低摆幅差分信号(LVDS)技术进行了研究。LVDS技术的核心是采用了极低的电压幅度高速差分的传输数据,能够实现点对点或一点对多点的连接。本文使用了verilog语言编写了LVDS关键技术中的时钟产生、数据的发射和数据的接收等模块,并且使用ModelSim6.2C仿真软件对上述模块进行了单元测试及系统验证,从而确认了上述系统功能的正确性,为以后解决高速数据处理问题提供了很好的参考方案。更多还原

【Abstract】 With the rapid development of video on demand, high-definition TV, VoIP and others, future optical networks will require better performance and higher capacity, especially in broadband access networks. However, the traditional xDSL access methods for these services can not meet the demand very well, so the emergence of new technologies is urgent needed. In this way, the passive optical network (PON) has aroused much attention and Time Division Multiplexing Passive Optical Network (TDM-PON) technology has been commercially available. However, the user can only get the limited bandwidth because many users share the bandwidth resources. As the result, the limited bandwidth can not meet future requirement. More over, it is difficult to manage the time slot. Fortunately, Wavelength Division Multiplexing Passive Optical Network (WDM-PON) can address these issues well and WDM-PON has been considered as a promising solution for the next-generation of FTTx. In this thesis, carrier reused and multicast transmission technologies in WDM-PON are main research works. At the beginning, it introduces the basics of access networks and analyzes WDM-PON system, so the significance of this research work is emphasizes. In order to achieve low-cost of ONU in WDM-PON system, the problem of“colorless”should be solved firstly. Uplink carrier re-modulation technique is a promising scheme to solve the problem. Based on the analysis on the existing carrier reused schemes, this thesis investigate on the IM format configuration and gives out the optimal performance point, which I think has direct value to the following research works. With the increasing of number of users’business in the WDM-PON system, multicast/broadcast business is also the main problem needed to solve. Based on the analysis on the existing multicast scheme, a new multicast scheme has been proposed, which is realized by using dynamic switching to choose the NRZ or Manchester formats. Though dynamic switching to select modulation format of downstream data, the multicast/broadcast technology can be realized. The new scheme can be flexible to achieve the multicast / broadcast service and it has many advantages such as simple architecture, and easy to recover clock.To further improve the high-speed data processing capabilities in optical network nodes, this thesis has studied the low voltage differential signaling (LVDS) technology. LVDS uses the very low voltage to transmit high-speed data and can achieve point to point or a multipoint connection. The Key technologies of LVDS including producing clock, sending data and receiving data are realized by verilog. Further, the ModelSim6.2C is used to simulate all single units and the whole system to verify the system functions. It provides a good reference resolved program for the high-speed data processing in the future.更多还原