Title :
Enhancement of the laser phase noise tolerance for star 16-QAM optical coherent systems
Author :
Liu, Jihong ; Chang, Gee-Kung
Author_Institution :
Sch. of Electron. Eng., Xi´´an Univ. of Posts & Telecommun., Xi´´an, China
Abstract :
An efficient bit-to-symbol mapping method for star 16-quadrature amplitude modulation (16-QAM) is proposed in this paper, which is similar to Gray coding for square 16-QAM. With the consideration of optimal ring ratio of constellation, our simulation results show that a linewidth of 3MHz per laser can be tolerated for star 16-QAM optical coherent systems with SNR penalty of 1dB at BER of 10-3, which is much better than that of square 16-QAM. Further optimization possibility with variable number of points on each of the rings for star 16-QAM constellation is also discussed.
Keywords :
Gray codes; error statistics; laser noise; optical communication equipment; phase noise; quadrature amplitude modulation; BER; SNR penalty; bit-to-symbol mapping method; gray coding; laser linewidth; laser phase noise tolerance; optical coherent systems; optimal ring ratio; star 16-QAM constellation; star 16-quadrature amplitude modulation; AWGN; Abstracts; carry phase estimation; coherent optical communication; constellation; laser linewidth; laser phase noise; star 16-quadrature amplitude modulation;
Conference_Titel :
Communications and Photonics Conference and Exhibition, 2011. ACP. Asia
Conference_Location :
Shanghai
Print_ISBN :
978-0-8194-8961-6
