The Research Of Re-modulation WDM-PON Based On Different Modulation Formats

With the Triple-play, Mobile Internet, Cloud services and other new technologies rapidly spreading into people’s daily life, the pressure of high-speed transmission has been from the core network down to the access network. In order to satisfy the requirement of large-scale deployment TD-LTE, telecom operators has focused on customer premises network which can carry IPTV, HDTV, VOD, and P2P applications as well. Therefore, WDM-PON as the ultimate direction of access technology can solve above problem relying on its high bandwidth, good security and strong capacity of multimedia services. However, the introduction of WDM-PON also indirectly strengthened dispersion and nonlinear effects. It is great necessary that new technology such as advanced modulation formats should be employed, especially the application of the Joint modulation structure, which can improve the performance of the WDM-PON. Moreover, wavelength reuse technology based on re-modulation will effectively reduce the system cost, and promote WDM-PON commercialization process.In this paper, research has been concentrated on WDM-PON and the advanced modulation formats. First of all, the optimization solutions of WDM-PON’s key technology has been proposed, including a new type of light source based on supercontinuum and comb filter, a hybrid structure of WDM-TDM-PON used intelligent ODN technology, standardized networking employed colorless ONU. Secondly, two advanced modulation formats DQPSK and IRZ have been studied, Analysis and simulation result reflect that both of them have high dispersion tolerance, nonlinear tolerance and spectral efficiency. On this basis, a new octal format IRZ-DQPSK has generated combined with IRZ and DQPSK, and this structure also has a good dispersion and nonlinear suppression. Finally, the article proposes two WDM-PON network structures. The former employs10Gbps DQPSK downstream and IRZ re-modulation, which is more suitable than the commonly scheme used NRZ in demand of ONU rapid growth. The latter is based on IRZ-DQPSK downstream and RSOA re-modulation. The structure realizes channel management of unicast and multicast services by wavelength selective switch smoothly.In conclusion, based on WDM-PON and advanced modulation formats in this paper, two networking solution accord with the future direction of high-speed transmission between customer premises network and central station. Furthermore, both of them enhance the multi-service carrying capacity and guarantee a large amount of information interaction. The simulation results demonstrate the feasibility of the two programs, which is of great significance to promote the further development of the WDM-PON.