Spatial correlation models for total co-channel interference and carrier-to-interference ratio in mobile cellular systems

Shadow fading, an inevitable phenomenon caused by obstructions in the propagation path, will cause large variations in the received signal strength for mobile radio environments. The spatial correlation of the shadowing effects is exponentially decayed by the increase in distance between any two separate positions. Variations in the shadowing effects are generally modeled as a Gaussian-Markov stochastic process. In this work, two Gaussian-Markov stochastic models have been proposed to characterize the spatial correlation properties and the variations in the total co-channel interference (CCI) as well as in the carrier-to-interference ratio (CIR) for downlink channels in mobile cellular systems. The numerical and simulation results show that these two models precisely characterize the spatial correlation properties of total CCI and CIR; good accuracy is guaranteed for different propagation environments, and the estimation errors for the standard deviations of the variations are limited to about 0.2 dB. The proposed models can be applied to the applications, such as the design of handoff schemes, link performance prediction, link adaptation control, and performance simulations