Fast-Convergence Digital Signal Processing for Coherent PON using Digital SCM

It is foreseeable that the 100 Gb/s/ $\lambda$ and beyond passive optical network (PON) will be required in future access networks to meet explosive growth of data traffic. The coherent systems could a promising solution for 100G PON. Coherent PON using digital subcarrier multiplexing (DSCM) can provide flexible bandwidth allocation large number subscribers by dividing subcarriers DSCM signal into time slots time-and-frequency division multiple access. When unit allocated new subcarrier, processing (DSP) should converge fast slot ensure low handoff latency real-time allocation. However, traditional DSP hard realize convergence due blind complex algorithms. In this paper, we design specific training sequence (TS) structure propose data-aided achieve feasibility proposed scheme experimentally verified an 8 Gbaud/SC×8 SCs 400 Gb/s-net-rate with 16 quadrature amplitude modulation. experimental results show jointly realized TS 416-symbol 52 ns duration. receiver sensitivity at 20% soft-decision forward error correction limit approximately -27 dBm power budget about 35.5 dB achieved booster amplifier.