Abstract: To improve the anti-fading performance of symmetric extended binary phase shift keying(EBPSK) modulation system and simplify the demodulator architecture, a (S-EBPSK) is proposed in this paper.The modulation signals are characterized with symmetric waveforms, and the simple and effective demodulation method is proposed, which impacts the filter added with comparison detection method.Both the theoretical power spectrum expression and the BER expression are deduced in detail.It is demonstrated by simulation that this scheme is simplified and valid.In addition, the S-EBPSK modulation system has advantages in both the additional white Gaussian noise(AWGN) channel and fading channel.