Voice and data services in multicode and variable spreading factor DS-CDMA systems

This paper analyzes the uplink capacity of multicode and variable spreading factor DS-CDMA cellular systems which accommodate users with different transmission rate requirements. It takes into account imperfect power control on slow signal fluctuations due to shadowing, the presence of Rayleigh fading and random location of the users. The circumstance where the portable transmits to the nearest base station is examined; when shadowing only is present, the possibility that the user chooses the least interfered among N_c nearest base stations is also considered. System capacity is determined analytically, employing two distinct approximations featuring low computational costs, as well as by simulation. The latter approach allows us to compare the accuracy of the analytical approximations for a wide range of system parameters.