DocumentCode :
61429
Title :
Carrier Phase Estimation Through the Rotation Algorithm for 64-QAM Optical Systems
Author :
Bilal, Syed Muhammad ; Bosco, Gabriella ; Jingchi Cheng ; Lau, Alan Pak Tao ; Chao Lu
Author_Institution :
Dipt. di Elettron., Politec. di Torino, Turin, Italy
Volume :
33
Issue :
9
fYear :
2015
fDate :
May1, 1 2015
Firstpage :
1766
Lastpage :
1773
Abstract :
A novel low-complexity two-stage digital feed-forward carrier phase estimation algorithm based on the rotation of constellation points to remove phase modulation for a 64-ary quadrature amplitude modulation (QAM) system is proposed and analyzed both experimentally and through numerical simulations. The first stage is composed of a Viterbi and Viterbi (V&V) block, based on either the standard quadrature phase shift keying (QPSK) partitioning algorithm using only Class-1 symbols or a modified QPSK partitioning scheme utilizing both Class-1 and outer most triangle-edge (TE) symbols. The second stage applies the V&V algorithm after the removal of phase modulation through rotation of constellation points. Comparison of the proposed scheme with constellation transformation, blind phase search (BPS) and BPS+MLE (maximum likelihood estimation) algorithm is also shown. For an OSNR penalty of 1 dB at bit error rate of 
, the proposed scheme can tolerate a linewidth times symbol duration product ( 
) equal to 
, making it possible to operate 32-GBd optical 64-QAM systems with current commercial tunable lasers.
Keywords :
error statistics; laser tuning; maximum likelihood estimation; optical communication equipment; optical modulation; phase modulation; quadrature amplitude modulation; quadrature phase shift keying; 64-QAM optical systems; 64-ary quadrature amplitude modulation system; BPS+MLE algorithm; Class-1 symbols; OSNR penalty; V&V algorithm; Viterbi and Viterbi block; bit error rate; blind phase search; constellation point rotation; constellation transformation; linewidth; low-complexity two-stage digital feedforward carrier phase estimation algorithm; maximum likelihood estimation; modified QPSK partitioning scheme; noise figure 1 dB; optical 64-QAM systems; phase modulation removal; rotation algorithm; standard quadrature phase shift keying partitioning algorithm; symbol duration product; triangle-edge symbols; tunable lasers; Adaptive optics; Partitioning algorithms; Phase estimation; Phase noise; Phase shift keying; Quadrature amplitude modulation; Bit error rate (BER); Viterbi & Viterbi algorithm; Viterbi and Viterbi (V&V) algorithm; carrier phase recovery; quadrature amplitude modulation (QAM); rotation algorithm (RA); triangle edge (TE); triangle edge (TE) symbols;
fLanguage :
English
Journal_Title :
Lightwave Technology, Journal of
Publisher :
ieee
ISSN :
0733-8724
Type :
jour
DOI :
10.1109/JLT.2015.2402441
Filename :
7038197
Link To Document :
