title: Performance analysis of coherent optical 8-star QAM systems using decision-aided maximum likelihood phase estimation.
abstract: An approximate bit-error rate (BER) expression of 8-star quadrature amplitude modulation (QAM) in the presence of a phase estimation error is derived. The accuracy of the approximate BER is verified via numerical integration of the conditional BER and the Monte-Carlo (MC) simulations. This approximation allows quick estimation of the BER performance and prediction of laser linewidth tolerance, and also facilitates optimization of the ring ratio.
authors.affiliation: Department of Electrical & Computer Engineering, National University of Singapore, Singapore 117576, Singapore.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Zhang
authors.forename: Pooi-Yuen
authors.initials: PY
authors.lastname: Kam
authors.forename: Changyuan
authors.initials: C
authors.lastname: Yu