Self-phase modulation (SPM) effect on performance of 40 Gbit=s (3 13.33 Gbit=s) optical duty-cycle division multiplexing (O-DCDM) over 400 km (5 80 km) standard single mode fiber (SSMF) based on three different dispersion compensation schemes is investigated by simulation. The result shows that the SPM effect is very strong in dispersion pre-compensation compared to postcompensation. Further reduction in SPM effect is observed by combination of pre-and post-compensation with the optimum pre-compensation value of around 215 ps=nm. The simulation is performed at different launched power into dispersion compensation fiber (DCF). The range between 6 to 8 dBm is observed as the optimum power for all dispersion compensation schemes. The highest SPM threshold is observed when dispersion pre-and post-compensation are used together, which is around C6:7 dBm. In addition, the optimum range of launched power into SSMF for different transmission distances from 80 km to 1280 km is also presented.