Asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) is theoretically more power efficient but less spectrally efficient than DC-bias OFDM (DCO-OFDM), with less power allocating to the informationless bias component by only using odd index sub-carriers. Layered/Enhanced asymmetrically clipped optical orthogonal frequency division multiplexing (L/E-ACO-OFDM) has been proposed to increase the spectral efficiency of ACO-OFDM. In this letter, we experimentally demonstrate a 30-km single mode fiber transmission using L/E-ACO-OFDM at 4.375 Gbits/s. Using a Volterra filter based equalizer, 2-dB and 1.5-dB Q-factor improvements for L/E-ACO-OFDM comparing with DCO-OFDM can be obtained in back-to-back and 30-km fiber transmission respectively.