Research Of Burst Mode Transmitter And Receiver In GPON System

With deepening extent of social information unceasingly, the demand of diversification of services and bandwidth by users is increased, which propels PON coming on an stage in communication again. PON is a point to multipoint technology, which consists of OLT(Optical Line Termination),ONU(Optical Network Unit) and ODN(Optical Distribution Network).The downstream data is optical carrier in the broadcast mode with TDM(Time Division Multiplexing) from OLT, while the upstream data multiplexed with TDMA(Time Division Multiplexed Access) are transmitted in burst mode from the ONUs. So far, there are three PON technology: APON,EPON and GPON. GPON is the most potential option for access network because of its higher speed, better characteristic and price ratio and unsymmetry, which can adapt to FTTH.This paper introduces the development evolution of PON simply and shows bright future of GPON by contrasting EPON and GPON being attended to by the field of optical communication. Afterward, burst mode transmitter and burst mode receiver which can adapt to GPON system are study emphasily. Because a GPON system is a point to multipoint system, transmitter of OLT and receiver of ONU are work in continuous mode, while transmitter of ONU and receiver of OLT must be work in burst mode. So the circuit designs of burst mode tranceiver have some of great differences which enbody Automatic Power Control, Preamplifier, Clock and Data Recovery. At the same time, because of burst mode, parameters of transmitter of ONU and receiver of OLT (for example, average power, sensitivity) are differ from conventional transmitter and receiver. what's more, There is some new characteristic, such as Tx enable/disable time, dynamic range ,and so on.