Abstract :
The effects of the `near-far´ problem on the Direct Sequence Code Division Multiple Access (DS/CDMA) system performance is investigated, for nonfading and Rayleigh faded channels, for spread spectrum mobile communication, respectively. For this purpose, the near-far situation is considered for various values of the interference to desired signal power ratios (αi), and for different number of users (K). Results obtained in this study show that the error probability degrades substantially as the number of users in the system grows, or as the interfering signals´ strength increases. It is also noticed that the performance deteriorates in the Rayleigh fading channel as compared to the nonfading case due to the near far problem, which results in a severe reduction in the multiple access capability of the DS/CDMA system
