Title :
Asynchronous linear optical sampling for monitoring impairments in multilevel signal modulation format generation
Author :
Wen, He ; Ye, Wang ; Nie, Siqi ; Zheng, Xiaoping ; Zhang, Hanyi
Author_Institution :
Dept. of Electron. Eng., Tsinghua Univ., Beijing, China
Abstract :
We propose a general method to monitor the impairments in high speed multilevel signal modulation format generation induced by improper setting and time-drifting of modulator bias offset based on signal constellation diagram. Using asynchronous linear optical sampling technique, we can obtain both the amplitude and phase information of the signal under test with a high time resolution and data speed transparency. We successfully recovered the constellation diagrams of 10Gbaud quadrature phase shift keying (QPSK) after a series proposed signal processing algorithms. Several common types of constellation distortion were observed with the manual tuning of the modulator bias. It proved the effectiveness of the proposed method.
Keywords :
amplitude modulation; optical communication; optical modulation; optical tuning; quadrature phase shift keying; signal processing; transparency; amplitude information; asynchronous linear optical sampling technique; data speed transparency; high time resolution; impairments monitoring; manual tuning; modulator bias offset; multilevel signal modulation format generation; phase information; quadrature phase shift keying; signal constellation diagram; signal processing algorithms; signal under test; time-drifting; Abstracts; Optical modulation; Linear optical sampling; carrier phase estimation; multilevel signal modulation; performance monitoring;
Conference_Titel :
Communications and Photonics Conference and Exhibition, 2011. ACP. Asia
Conference_Location :
Shanghai
Print_ISBN :
978-0-8194-8961-6