There is signal-signal beating interference (SSBI) when the orthogonal frequency division multiplexing (OFDM) signal is detected by PIN after transmiting over the fiber in 60 GHz OFDM radio-over-fiber (RoF) system. The interleaved configuration of training sequence of OFDM signal is proposed to decrease the influence of the SSBI. The experimental results show that after the 2.5 Gb/s interleaved OFDM signal transmitting over 20 km single mode fiber in 58 GHz millimeter-wave system, the power penalty of the interleaved OFDM signal is only 0.5 dB at the bit error rate (BER) of 10-3 without dispersion compensation. In comparison, the power penalty of the continued OFDM signal under the same conditions is 2 dB. It is demonstrated that the fiber transmission performance of the interleaved OFDM signal is better than the continued OFDM signal in robust tolerance against SSBI.