Performance considerations of code division multiple-access systems

The performance of code division multiple-access (CDMA) systems is determined using direct-sequence spectral spreading. Asynchronous users are assumed so that there is no network control. Under relatively ideal conditions, the degradation in system performance as a function of the number of users is shown to have a threshold effect. This basic limitation in the number of users of the system is further limited if the powers are unequal. For two users, system performance as a function of their power ratios also has a threshold effect. System performance as a function of the amount of spectral spreading is determined. The performance of both coded and uncoded systems is predicted.