Optimum receivers for non-linearly distorted OFDM signals in wireless-over-fiber applications: Impact of antenna noise

In this paper, we study the effect of uplink noise on the optimality of the receiver structure proposed in [1][2]. This optimum receiver is composed by a demodulator that extracts a set of sufficient statistic, and by an ML detector that uses the demodulator output to estimate the original data. We concentrate on Intensity modulation-direct detection (IM/DD) radio-over-fiber (RoF) uplink system when OFDM signals suffer from noise generated by the antenna and photodiode and from nonlinear distortion. The results show that for small and medium modulation index values, the uplink noise maintains its Gaussian distribution and the optimum receiver still outperforms the conventional.