A method to generate Single Sideband Return-to-Zero Signal(SSBRZ) is introduced by deriving formulas. One sideband of the generated SSBRZ signal is suppressed more effectively without distortion of the optical pulses. 40Gb/s single channel transmission of Return-to-Zero(RZ) signal,Carrier Suppressed Return-to-Zero(CSRZ) signal and SSBRZ signal over single mode fiber(SMF) are simulated. The results show that SSBRZ is superior to RZ and CSRZ against fiber nonlinearities when chromatic dispersion is completely compensated.