Outage events in a DS-CDMA wireless system with closed-loop power control
Fortunato Santucci, Fabio Graziosi · 2002
This paper deals with characterization of second order outage statistics in the reverse link of a DS-CDMA wireless system with closed-loop power control. By means of a specifically developed simulation tool, the mean and the autocovariance of the received power level of the user signal and of the signal-to-interference ratio (SIR) at the base station are estimated. Both cases of the power control algorithm operating on a power target basis and on a SIR target basis are considered. The average rate and duration of related outage events are estimated, as well. In this framework minimum duration outages are also considered. Numerical results are reported as obtained in a multicell environment with Rayleigh fading and shadowing. It is seen that a slow power update may determine a sudden increase of the standard deviation of the user signal power and SIR residual fluctuations. Moreover, the residual burstiness of the controlled channel may be responsible of long outages.