TechRxiv
Transceiver_IQ_Imbalance_arxiv.pdf (3.79 MB)
Download file

Widely Linear Filtering for Multi-Impairment Compensation in Coherent Optical Systems

Download (3.79 MB)
preprint
posted on 29.06.2021, 05:24 by Rekha YadavRekha Yadav, Lakshmi Narayanan Venkatasubramani, Ravinder David Koilpillai, Deepa Venkitesh
We propose a blind joint equalization algorithm for M-QAM signals based on a widely linear filtering approach. The proposed scheme jointly compensates receiver IQ imbalance and polarization mixing, along with carrier recovery, followed by transmitter IQ imbalance compensation. We first investigate the proposed scheme's tolerance to transceiver IQ Imbalance, polarization mixing, phase noise and frequency offset through numerical simulations for 32 GBd PM-16QAM and PM-64QAM signals and compare its performance with the conventional digital processing algorithms. Further, with the proposed algorithm, we experimentally demonstrate the improvement in Q2 value to up to ~ 1.22 dB for a 32 GBd PM-16QAM and ~ 3.72 dB for a 16 GBd PM-64QAM signal with a phase imbalance of 9o. We show that the MSE convergence of the proposed joint equalizer is much faster than conventional DSP algorithms. Deployment of such an equalizer in optical communication systems is beneficial due to its improved tolerance to multiple impairments, albeit with increased complexity.

Funding

Indian Institute of Technology Madras, Chennai, India

Ministry of Human Resource Development, Government of India

Office of Principal Scientific Advisor, Government of India

History

Email Address of Submitting Author

ee18s046@smail.iitm.ac.in

ORCID of Submitting Author

0000-0002-4834-7762

Submitting Author's Institution

Indian Institute of Technology Madras, Chennai, India

Submitting Author's Country

India