An AF relay splits an FBMC transmission link into a two-hop channel. The receiver implements a parallel multistage FBMC demodulator/equalizer that is suitable for fading channels whose frequency response cannot be considered flat over the subcarriers. The signal quality at the output of such a receiver is characterized in terms of signal-to-noise-plus-distortion ratio (SNDR), that takes into account the residual interference after equalization and the effect of the noise collected on both hops. The SNDR is then used to estimate the spectral efficiency of the link. The comparison with the direct link shows that the AF-relay scheme offers some gain, especially in lossy environments with high path-loss exponent.