Capacity analysis of an integrated voice and data CDMA system

In Code Division Multiple Access (CDMA) systems, capacity estimation is a very important task in network planning. Unlike other multiple access systems, the CDMA system capacity is determined by the total amount of interference accepted in the allocated frequency spectrum. At present, the traffic models for voice CDMA systems have been developed and are widely used. The purpose of this thesis is to develop traffic models to approximate the system capacity in a network with integrated services in IS-95 CDMA systems. The thesis focuses on the capacity of the reverse link, that is the communication link from an user terminal to a cellular base station.;A new and simple approximation method is developed to estimate the Erlang capacity in a homogeneous CDMA system. This approximation is then extended to include a hybrid voice and data system. The traffic models for user and Erlang capacities are introduced, and the difference in the grades of service and the effect of cell loading between these models are discussed. The traffic model for a network with different bit rates is also developed, and the impact of different parameters in the traffic models are studied. The model is used to determine the Erlang and user capacity tradeoffs between different bit rates.;A model for the bursty data service is studied, and it is based on the Pareto distribution. It is expected that the bursty data affects system capacity adversely. In this thesis, the burstiness is incorporated into the traffic model and the Erlang capacity for bursty packet data is determined. Furthermore, the model for the channel usage based on the Erlang capacity in the integrated voice and data system is enhanced to estimate the number of channel units required at the base stations.