Variance normalizing transform for performance improvement in radio-over-fiber systems

Radio-over-fiber (ROF) will be an indispensable part of future wireless communication networks to support backhaul connectivity. The performance of ROF communication system is impaired with signal-dependent distortions in the optical fiber link such as shot noise and relative intensity noise. In this paper, these signal-dependent distortions of the ROF channel are analyzed in more details and a variance normalizing technique is proposed to normalize the noise power. In effect, the signal-dependent noisy ROF channel is converted to a signal-independent additive white Gaussian noise channel for which the conventional signaling techniques are efficient. The results show significant performance improvements for the proposed technique in terms of signal-to-noise ratio.