Outage capacity in CDMA systems using receive antenna diversity and fast power control

In this paper, we analyze the outage capacity improvements in multi-cellular code division multiple access (CDMA) systems using receive antenna diversity and fast power control schemes that can track multipath fading. The channel is modelled as slowly varying Rayleigh fading with lognormal shadowing and path loss. Closed form expressions are obtained for the outage capacity of the system by approximating the total intercell and intercell interference distributions. We show that by controlling the power level of a user at the output of the diversity combiner and imposing the condition that the user denies transmission when in deep fade, the average intercell interference level of the system is significantly reduced. As a result of this reduction, we demonstrate both analytically and through simulations that the outage capacity of the system is improved more than the linearity with increasing number of antenna elements.