Estimated bit error probability of DS-SSMA/MDPSK with differential phase detector on satellite mobile channel

The performance of direct-sequence spread-spectrum multiple-access (DS-SSMA) systems with M-ary differential phase shift keying (MDPSK) and a differential phase detector (DPD) are estimated on the satellite mobile channel (SMC) which includes Gaussian and Rayleigh channels as the special cases. Numerical results are presented for the system with one of three types of chip waveforms (rectangular, cosine and root Nyquist filtering (RNF)), and binary or complex random signature sequences. They show that the system with the complex random signature sequences outperforms the system with the binary random signature sequences on Gaussian and Rician (K=10) channels, while on a Rayleigh channel both systems perform similarly; the system with 2×I users and BDPSK signalling format outperforms that with I users and QDPSK for Gaussian and Rician (K=10) channels; and from the point view of both bandwidth efficiency and antimultipath effects, the cosine pulse shaping is the best choice of the three pulse shape functions, although the system with the RNF has the highest bandwidth efficiency