Markov modeling of the inner-loop power control [cellular CDMA systems]

This work proposes an analytical method to evaluate the performance of the inner-loop power control in CDMA systems. The transition of the signal power is modeled as a Markov process. By using Markov properties, the probability density function (PDF) of the transmitted signal power can be expressed by the steady-state eigenvector obtained from the Markov chain. The resulting method does not require time-consuming simulations and field measurements to evaluate the bit error rate (BER). The result also covers the influence caused by the practical implementation factors for the power control loop, such as the erroneous estimation of the signal-to-interference ratio (SIR), the power control command error, the step size, and the feedback delay of the loop. The model is validated by comparing the analytical results with simulations.