Study On Intensity Modulated RSOA Based Optical OFDM-PONs And Their Dynamic Resource Control Scheme

For its distinguish dispersion tolerance,high spectrum efficiency,passive optical network based on optical orthogonal frequency division multiplexing(OOFDM)technology is considered to be candidates for the next generation optical access network technology and has become a hotspot.How to reduce the implementation cost of independent optical source on ONU side of the OFDM-PON system and make full use of the bandwidth resources are the two key factors to realize the practical application of the technology.In this paper,we focus on the application of low-cost RSOA intensity modulator on OFDM-PON system and propose two solutions to improve the system performance through making the numerical simulation analysis and experimental verification.Finally,we work on the dynamic resource control scheme of OFDM-PON system.In conclusion,the main contribution of this paper includes the following aspects:1)We establish a simulation model of intensity modulation direct detection(IMDD)OFDM-PON transmission system based on RSOA.The theoretical model and micro parameters of the commercial RSOA intensity modulator are optimized through numerical simulation and data fitting with the experimental results of the dual band OFDM-PON transmission system experiment based on RSOA.2)Using optimized theoretical model and RSOA micro parameter,we analyze the influence of RSOA intensity modulator frequency chirp on the system performance and propose a scheme that using adaptive bit and power loading technology along with the character of frequency chirp to improve the OFDM-PON system capacity.We propose an OFDM signal transmission system scheme that supports 40Gb/s@25km SSMF under the condition of using single RSOA modulator without introduction any other optical domain or electric domain equalization technique.3)In this paper,we overcome the faulty of traditional single-RSOA-based self-seeding architecture by using dual-RSOA-based colorless self-seeding architecture instead.In this way,we successfully reduce the influence of optical signals' RIN and residual intensity modulation crosstalks and obtain 10Gb/s transmission capacity over 25 km SSMF transmission system.4)By introducing the PHY Link cross layer control module,the subcarrier bandwidth mapping based on adaptive bit and power loading is realized and the complexity of the multi-dimensional bandwidth resource allocation is simplified.On this basis,we propose PMB-DBA resource allocation scheduling mechanism and optimize the bandwidth resource allocation method.Finally,the downlink bandwidth scheduling algorithm of OFDM-PON is studied and the improved scheme of related MAC layer stack is proposed.