Title :
Compensation of Frequency Offset for 16-QAM Optical Coherent Systems Using QPSK Partitioning
Author :
Fatadin, Irshaad ; Savory, Seb J.
Author_Institution :
Nat. Phys. Lab., Teddington, UK
Abstract :
The performance of a feed-forward carrier frequency recovery algorithm for 16-quadrature amplitude modulation (QAM) optical coherent systems is investigated using the quaternary phase-shift keying (QPSK) partition scheme. The frequency estimation technique, which employs only a subset of the 16-QAM symbols with the QPSK partition, is demonstrated to be effective when applied prior to the carrier phase recovery. Frequency offset of 10-1 times the symbol rate is shown to be tolerable at a bit-error rate (BER) of 10-3 with combined linewidths symbol duration products of 10-4 .
Keywords :
error statistics; frequency estimation; light coherence; optical communication; quadrature amplitude modulation; quadrature phase shift keying; set theory; 16-QAM optical coherent system; 16-QAM symbol subset; 16-quadrature amplitude modulation; QPSK partitioning; bit error rate; carrier phase recovery; feedforward carrier frequency recovery algorithm; frequency estimation technique; frequency offset compensation; quaternary phase shift keying; symbol rate; Estimation; Frequency estimation; Frequency modulation; Lasers; Partitioning algorithms; Phase shift keying; Quadrature amplitude modulation; Carrier phase recovery; frequency offset; quadrature amplitude modulation (QAM); quaternary phase-shift keying (QPSK) partition;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2011.2158994
