Erlang capacity of a power controlled integrated voice and data CDMA system

In a previous paper by A.M. Viterbi and A.J. Viterbi (see IEEE J. Sel. Areas Commun., vol.11, no.6, p.892-900, 1993), an analytical approach to computing the Erlang capacity of a voice-only CDMA system was presented. Capacity was defined as the maximum Erlangs of voice traffic that can be supported while limiting the total received interference and noise below a threshold, 99% of the time. In this paper, we evaluate the Erlang capacity of a CDMA system with voice and data users. The outage condition is first related to power control feasibility. It is shown that the outage condition is more stringent and hence ensures power control feasibility. The outage condition is then extended to the case of a CDMA system with voice and data users. An approximate analysis that takes into account imperfect power control, activity factors and different quality requirements is presented. Simulations are used to validate the approximate analysis.