- In this paper, we introduce a nonlinear equalizer using the radial basis function (RBF) network for electronic dispersion compensation in optical communication systems with on-off keying and a direct-detection receiver. The RB method introduces a nonlinear equalization technique that is suitable for optical communication direct-detection systems that include nonlinear transformation at the photodetector. A bit error rate performance comparison shows that the RBF equalizer outperforms the conventional linear feedforward equalizer. In addition, it is shown that, in optically amplified systems, the RBF equalizer improvement is increased even further. Finally, the feasibility of the RBF method is validated by experimental results.