Nonlinearity Reduction in Subcarrier Multiplexed Radio Over Fiber Systems
Tony Jose1, Vijayakumar Narayanan2

1Tony Jose, Fiber Optics & Photonics Laboratory, Department of Electronics & Communication Engineering, College of Engineering Trivandrum, Thiruvananthapuram (Kerala), India.
2Vijayakumar Narayanan, Department of Electronics & Communication Engineering, Government Engineering College, Barton Hill, Thiruvananthapuram (Kerala), India.  

Manuscript received on 10 October 2017 | Revised Manuscript received on 18 October 2017 | Manuscript Published on 30 October 2017 | PP: 37-40 | Volume-7 Issue-1, October 2017 | Retrieval Number: A5177107117/17©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: In subcarrier multiplexed (SCM) Radio over Fiber (RoF) systems, multiple radio frequency (RF) signals are combined in the electronic domain and transmitted simultaneously by modulating them on high-frequency optical carriers. The harmonic and intermodulation distortions generated due to the inherent nonlinearity of the laser transmitters causes severe performance degradation in multiuser RoF systems. This work aims to reduce the adverse effects due to the laser diode nonlinearity using external mechanisms. A predistortion technique is suggested for the suppression of the additional frequency components generated. A simulation study on the effect of nonlinearity on a three-user SCM-RoF system is carried out. A predistortion technique in which the input signals are preprocessed to mitigate the nonlinear effects is introduced into the system and the performance enhancement is verified.
Keywords: Harmonic Distortion, Laser Diode, Nonlinearity, Predistortion, Radio over Fiber, Subcarrier Multiplexing.

Scope of the Article: Radio Over Fiber