Chromatic Dispersion-Based Modulation Distortion Compensation for Analog Radio-Over-Fiber: Performance Improvement in OFDM Transmission

In radio over fiber systems, it is desirable to increase the depth of optical modulation in favor of large signal-to-noise ratio. The authors have analytically predicted and experimentally demonstrated the compensation of signal distortions caused by modulator nonlinearity, using chromatic dispersion. In this paper, we report experiments on a radio-over-fiber system for orthogonal frequency division multiplexed radio signal transmission and its performance improvements achieved by the above effect. From experimental results, it was found that signal-distortion compensation capability by chromatic dispersion is limited when the receiver noise is dominant or the modulation depth is low. However, for higher modulation depths, when an appropriate amount of dispersion is applied, the bit error rate improves regardless of the signal-to-noise ratio at the receiver end. By applying fiber dispersion, the maximum improvement of the power penalty was estimated up to 3 dB in the proposed system.