Title :
High-Dynamic-Range Wireless-Over-Fiber Link Using Feedforward Linearization
Author :
Ismail, Tabassam ; Liu, Chin-Pang ; Mitchell, John E. ; Seeds, Alwyn J.
Author_Institution :
Univ. Coll. London, London
Abstract :
We demonstrate the implementation of feedforward linearization at 5 GHz, which is the highest operating frequency yet reported, with 500-MHz linearization bandwidth having at least 24-dB distortion suppression. Simultaneous reduction of 26-dB third-order intermodulation distortion and 7-dB laser-noise reduction is achieved at 5.2 GHz, leading to enhanced spurious-free dynamic range of 107 dB (1 Hz) in a directly modulated uncooled semiconductor laser for applications in wireless-over-fiber (WoF) systems. This paper also provides detailed analysis on feedforward, theoretical distortion reduction, criteria for component selection, and the effect of dispersion. The effectiveness of feedforward in a multichannel system is demonstrated at 5.8 GHz for fixed wireless systems, such as WiMAX. These results suggest that the feedforward-linearization arrangement can make practical multichannel and multioperator WoF systems.
Keywords :
WiMax; feedforward; linearisation techniques; microwave photonics; optical communication equipment; radio-over-fibre; semiconductor lasers; telecommunication channels; WiMAX; bandwidth 500 MHz; directly modulated uncooled semiconductor laser; feedforward linearization; frequency 5 GHz; frequency 5.2 GHz; laser-noise reduction; multichannel system; multioperator WoF systems; theoretical distortion reduction; third-order intermodulation distortion; wireless-over-fiber link; Bandwidth; Dispersion; Dynamic range; Frequency; Intermodulation distortion; Laser applications; Laser noise; Laser theory; Lead compounds; Semiconductor lasers; Feedforward linearization; nonlinear distortion; spurious-free dynamic range (SFDR); uncooled lasers; wireless over fiber (WoF);
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2007.906823
