50G-PON标准进展及关键技术

摘要：50G-PON标准制定主要工作已基本完成，下行支持50 Gbit/s，上行支持12.5 Gbit/s、25 Gbit/s和50 Gbit/s。50G-PON支持GPON、XG(S)-PON、50G-PON三代共存。50 Gbit/s光接口指标采用OMA-TDEC参数体系，光模块发射光功率、消光比、TDEC指标可以相互补偿，核心是要满足光调制功率与TDEC的最小差值要求。50G-PON引入DSP均衡以提升接收灵敏度。为了发挥DSP均衡能力，TIA、LA不能采用限幅放大，需要支持线性放大。线性突发LDD、TIA、LA和BCDR是50G-PON突发收发关键芯片。50G-PON采用纠错能力更强的LDPC纠错技术以提升接收机灵敏度，与DSP集成可以支持软值LDPC。SFP尺寸的GPON、XG(S)-PON、50G-PON三代Combo是50G-PON OLT光模块的关键需求。模块结构布局和功耗是主要挑战。

关键词：50G-PON；数字信号处理均衡；低密度奇偶校验；突发收发；三代Combo

Abstract: The main work of 50G-PON standardization has been basically completed. The downlink supports 50G line rate, and the uplink supports 12.5 Gbit/s, 25 Gbit/s, and 50 Gbit/s triple line rate. The 50G-PON supports the coexistence of GPON, XG(S)-PON, and 50G-PON in one ODN. The 50G line rate optical interface specification uses the OMA-TDEC parameter method. The transmit optical power, extinction ratio, and TDEC parameters of the optical module can be mutually compensated. The core performance must meet the requirement of the minimum launch power in OMA minus TDEC value. 50G-PON introduces DSPs to improve the receiving sensitivity. To fully use the DSP equalization capability, the TIA and LA cannot use amplitude-limiting amplification but must support linear amplification. Linear burst LDD, trans-impedance amplifier, LA, and BCDR are key devices for 50G-PON upstream burst transmission. The 50G-PON uses LDPC error correction technology to improve receiver sensitivity and can integrate with the DSP to support soft-decision LDPC. The SFP type GPON, XG(S)-PON, and 50G-PON three-generation combo are key requirements for 50G-PON OLT optical modules. The module structure layout and power consumption are major challenges.

Keywords: 50G-PON; digital signal processor equalization; low-density parity-check; burst transmission; three-generation Combo