Title :
Study of IQ imbalance effect in direct-detection optical OFDM systems
Author :
Li, Xinying ; Shao, Yufeng ; Zou, Shumin ; Hou, Chunning ; Zheng, Xi ; Liu, Xiao ; Zhang, Junwen ; Fang, Wuliang ; Chi, Nan
Author_Institution :
The State Key Lab of ASIC & System, Department of Communication Science and Engineering, Fudan University, Shanghai, 200433, China
Abstract :
In-phase/quadrature-phase (IQ) imbalance can result in severe performance degradation in optical direct-detection orthogonal-frequency-division-multiplexing (DD-OFDM) systems. We build two optical back-to-back DD-OFDM systems, which implement double-sideband (DSB) and single-sideband (SSB) modulation, respectively. The tolerance to IQ imbalance of these two systems is analyzed and compared using error vector magnitude (EVM) and symbol error rate (SER). We find that, in the back-to-back case, the DSB system has stronger robustness to IQ imbalance than the SSB System. We further build two optical DD-OFDM systems each with 40-km transmission, which respectively implement DSB and SSB transmission. Similarly, we analyze and compare the tolerance to IQ imbalance of these two systems in terms of EVM and SER. We find that, however, in the case of 40-km transmission, the SSB system has stronger robustness to IQ imbalance than the DSB system. As a result, we conclude that, in the case of transmission, SSB modulation can enhance the tolerance to IQ imbalance of DD-OFDM systems.
Keywords :
Amplitude modulation; Application specific integrated circuits; Degradation; High speed optical techniques; OFDM modulation; Optical modulation; Optical receivers; Optical transmitters; Robustness; System performance; Back to back; DD-OFDM; DSB modulation; EVM; IQ imbalance; SER; SSB modulation; Timing jitter;
Conference_Titel :
Communications and Photonics Conference and Exhibition (ACP), 2009 Asia
Conference_Location :
Shanghai, China
Print_ISBN :
978-1-55752-877-3
Electronic_ISBN :
978-1-55752-877-3
