Line Coding And Orthogonal Modulation Research In Next Generation PON And Optical Label Switching

Access networks currently face three major problems,i.e,less coverage,slower network speed and higher tariffs.In order to overcome these three major problems and solve the bottleneck of the access network,passive optical network(PON,Passive Optical Networks)has become an important research topic in optical communication.The emergence of various emerging services has led to a continuous and rapid increase in user bandwidth demand,and the PON in the form of single multiplexing technology is no longer sufficient.In contrast,a hybrid of multiple multiplexing technologies is considered a promising next-generation access network technology.The nextgeneration PON is mainly in the form of TWDM PON with time and wavelength hybrid multiplexing.In the evolution to the next-generation PON,smooth upgrade and colorless ONU(Optical Network Unit)are two major challenges.In addition,due to the addition of new WDM PON,the data broadcast function is also a problem to be solved.Due to the emergence of new services such as various high-definition video,interactive network television,wireless data backhaul,and mobile multimedia,network switching traffic increases explosively.In order to overcome the rate bottleneck of electrical switching,reduce the cost of system upgrade,and realize the process of high-rate switching,the ASK/DPSK orthogonal optical label switching technology has been studied.However,the quality of the ASK payload signal and the DPSK label signal are limited by the extinction ratio,which is also a problem to be solved.Therefore,the application of simple line coding and orthogonal modulation in PON evolution,colorless ONU,data broadcast and optical label switching in backbone networks have been studied in this paper.Firstly,the three simple line codes of Manchester,4b5 b and 4b6 b are applied for the upgraded downlink signal.The crosstalk from the future PON downlink signal have been reduced.All signals achieve error free transmission.Smooth upgrade and transparency have been achieved in the PON at the same time.The development of this work mainly includes basic theoretical analysis,system simulation,experimental testing and comparative analysis of results.Secondly,to enable the new WDM PON to deliver broadcast signal,the future PON downlink signal adopts Manchester coding.The broadcast signal adopts the Pol SK modulation orthogonal to the ASK,and combines the uplink re-modulation technology to realize the smooth upgrade of the PON,the colorless ONU and the broadcast function.Through the system simulation and experimental test,the feasibility and effectiveness of the scheme have been verified.Finally,the inverse 4ppm line coding is applied to the ASK/DPSK orthogonal modulation label switching scheme as the payload signal coding before the ASK modulation.The simulation results show the extinction ratio improvement of at least 24 d B,and the quality of the label signal is guaranteed without sacrificing the extinction ratio of the payload signal.