Sensitivity analysis of the reverse link Erlang capacity of CDMA systems

In this paper, the performance of a CDMA mobile radio system is analyzed under different traffic loads. The major influential parameters are identified and their effect on traffic capacity is analyzed using a simulation model. New results have been obtained by analyzing the sensitivity of Erlang capacity to a range of CDMA network parameters namely call quality, shadowing, distance exponent, voice activity, and processing gain. Comparison of the results indicate that the most influential parameter is call quality while shadowing followed by the processing gain have the least effect. It is noted that when the offered load is low for the system under study, a change of a few Erlang in the offered traffic has insignificant effect on the blocking probability. As the traffic increases, and the call quality drops below an adequate threshold, there is a sudden increase in the sensitivity of the blocking probability to traffic load.