Open AccessBlind optical modulation format identification assisted by signal intensity fluctuation for autonomous digital coherent receivers
Author(s) -
Lin Jiang,
Lianshan Yan,
Anlin Yi,
Yan Pan,
Ming Hao,
Wei Pan,
Bin Luo
Publication year - 2020
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.372406
Subject(s) - quadrature amplitude modulation , phase shift keying , computer science , optics , modulation (music) , signal (programming language) , electronic engineering , telecommunications , bit error rate , physics , acoustics , decoding methods , engineering , programming language
A novel and blind optical modulation format identification (MFI) scheme assisted by signal intensity fluctuation features is proposed for autonomous digital coherent receivers of next generation optical network. The proposed MFI scheme needn't to pre-know OSNR value of incoming signal, even though it is well known that the intensity dependent features of the incoming signal changes as the change of OSNR performance. Here, the proposed scheme firstly utilizes two kinds of signal intensity fluctuation features, Godard's criterion error and intensity noise variance, to construct a two-dimensional (2D) plane where three different regions which consist of QPSK region, 8QAM region, mixed 16/32/64QAM region can be found. Thus, we can firstly identify QPSK and 8QAM from the 2D plane, and then partition Godard's criterion error method is introduced to further identify 16QAM, 32QAM and 64QAM in our proposed scheme. The performance of the proposed scheme is firstly verified by a series of numerical simulations in 28GBaud PDM-QPSK/-8QAM/-16QAM/-32QAM/-64QAM coherent optical communication systems. The results show that the lowest required OSNR values to achieve 100% recognition rate for all modulation format signals are even lower than or close to their corresponding theoretical 20% FEC limits (BER = 2.4 × 10 -2 ). Finally, the feasibility is further demonstrated via a series of proof-of-concept experiments among 28GBaud PDM-QPSK/-8QAM/-16QAM, and 21.5GBaud PDM-32QAM systems under back-to-back and long-haul fiber transmission links (from 320 km to 2000km). Experiment results show that the proposed scheme is robust to both linear and nonlinear noise.