Performance characteristics of the IS-95 standard for CDMA spread spectrum mobile communication systems

An IS-95 based mobile communication system is simulated and its performance characteristics in multipath fading environment is presented in this paper. A new software simulation methodology to implement the system using the dynamic system simulation environment, SIMULINK(R) in MATLAB(R) is also developed. The system consists of forward and reverse CDMA channel structures in the forward link (base station to mobile station) and reverse link (mobile station to base station) respectively. A three-stage measurement based multipath channel model consisting of path loss, lognormal fading and Rayleigh fading components is implemented. Channel impulse response measurements, also described as power delay profiles, of RF signals in the range of 800-900 MHz in multipath channels are used to estimate the structure of an optimum noncoherent combining RAKE receiver. This receiver shows considerable performance improvement over a four-way combining RAKE receiver.