Performance of cellular CDMA with voice/data traffic with an SIR based admission control

We analyze the performance of an SIR based admission control strategy in cellular CDMA systems with both voice and data traffic. Most studies in the current literature to estimate CDMA system capacity with both voice and data traffic do not take signal-to-interference ratio (SIR) based admission control into account. In this paper, we present an analytical approach to evaluate the outage probability for voice traffic, the average system throughput and the mean delay for data traffic for a voice/data CDMA system which employs an SIR based admission control. We show that for a data-only system, an improvement of about 25% in both the Erlang capacity as well as the mean delay performance is achieved with an SIR based admission control as compared to code availability based admission control. For a mixed voice/data system with 10 Erlangs of voice traffic, the improvement in the mean delay performance for data is about 40%. Also, for a mean delay of 50 ms with 10 Erlangs voice traffic, the data Erlang capacity improves by about 50%.