Research On The Key Techniques Of The Enhancement Of 10G/S/? WDM PON System Capacity

With the emerging of new high-bandwidth demands of all kinds of new applications,Passive Optical Network(PON)has been widely used in recent years.Wavelength Division Multiplexing Passive Optical Network(WDM PON)as an optical access network of high capacity,protocol transparency and good compatibility is one of the main technical solutions of Next-Generation PON(NG-PON).Increasing the system capacity and decreasing the costs of unit bandwidth is the main challenge of the evolution and development of WDM PON and is also one of the key problems to solve.In this paper,Several key techniques of enhancing the capacity of 10G/S/? WDM PON system are researched.The main research contents and results expand a?s blow.1.Design a channel-reuse lOGbps WDM PON system based on wavelength shift to improve spectrum efficiency and reduce the impact of Rayleigh-Backscattering(RB).Furthermore,design an optical amplification scheme based on Remote Pump Erbium-Doped Fiber Amplifier(RP-EDFA)and channel-reuse wavelength-shift WDM PON system to enhance the system coverage.Test results confirm that wavelength shift can effectively reduce the impact of RB in channel-reused scheme and RP-EDFA can increase the system coverage from 40km to 80km.2.Design a wavelength control scheme of tunable laser based on beat noise power detection to implement the colorless ONU in channel-reuse WDM PON system.Test results show that implementing accurate control of tunable laser by using microwave power detector of 1dB resolution to monitor the beat noise power can achive control accuracy above 0.05nm and is an effective colorless ONU scheme.3.Employing low baud rate and high-level modulation format is one of effective methods to increase spectral efficiency and system capacity.We design a 4-Pulse Amplitude Modulation(4-PAM)based on Reflective Semiconductor Optical Amplifier(RSOA)and coherent detection scheme of WDM PON upstream.Simulation tests show that the receiver sensitivity of coherent detection improves 13.5dB compared with direct detection.