Flexible Coherent Optical Access: Architectures, Algorithms, and Demonstrations

TL;DR

This paper presents architectures, algorithms, and real-time demonstrations of a coherent PON system supporting up to 256 users with peak rates of 100Gb/s upstream and 200Gb/s downstream, advancing beyond 50G PON.

Contribution

It introduces cost-effective architectures and low-complexity DSP algorithms for TFDMA-based coherent PON, with the first real-time demonstration supporting high user capacity and data rates.

Findings

Supports up to 256 users in real-time

Achieves 100Gb/s upstream and 200Gb/s downstream rates

Demonstrates feasibility of beyond 50G PON with coherent technology

Abstract

To cope with the explosive bandwidth demand, significant progress has been made in the ITU-T standardization sector to define a higher-speed passive optical network (PON) with a 50Gb/s line rate. Recently, 50G PON becomes mature gradually, which means it is time to discuss beyond 50G PON. For ensuring an acceptable optical power budget, beyond 50G PON will potentially use coherent technologies, which can simultaneously promote the applications of flexible multiple access such as time/frequency-domain multiple access (TFDMA). In this paper, we will introduce the architectures, algorithms, and demonstrations for TFDMA-based coherent PON. The system architectures based on an ultra-simple coherent transceiver and specific signal spectra are designed to greatly reduce the cost of ONUs. Meanwhile, fast and low-complexity digital signal processing (DSP) algorithms are proposed for dealing with upstream and downstream signals. Based on the architectures and algorithms, we experimentally demonstrate the first real-time TFDMA-based coherent PON, which can support at most 256 end users, and peak line rates of 100Gb/s and 200Gb/s in the upstream and downstream scenarios, respectively. In conclusion, the proposed technologies for the coherent PON make it more possible to be applied in the future beyond 50G PON.