Performance of Wideband Mobile Channel with Perfect Synchronism BPSK vs QPSK DS-CDMA

Direct-sequence code-division multiple access (DS-CDMA) is currently the subject of much research as it is a promising multiple access capability for third and fourth generations mobile communication systems. The synchronous DS-CDMA system is well known for eliminating the effects of multiple access interference (MAI) which limits the capacity and degrades the BER performance of the system. In this paper, we investigate the bit error rate (BER) performance of a synchronous DS-CDMA system over a wideband mobile radio channel. The BER performance is affected by the difference in path length ∆L and the number of arriving signals N. Furthermore, the effect of these parameters is examined on the synchronous DS-CDMA system for different users’ number as well as different processing gain Gp. In this environment and under the above conditions the performances of the BPSK(Binary Phase Shift Keying) and the QPSK (Quadrature Phase Shift Keying) modulations are compared. The promising simulation results showed the possibility of applying this system to the wideband mobile radio channel. Key-Words: BPSK, QPSK, Complex, Gain, Wideband , Synchronism, Direct, Sequence, CDMA, BER.