Distribution of ISR and Its Optimization in Performance Evaluation of Forward Link in Cellular Mobile Radio Systems

SUMMARY In CDMA systems, power control strategy is the most important issue since the capacity of the system is only interference-limited. For a better understanding of the effects of Forward Link Power Control Strategy on the outage probability in fading environments, this paper has presented a theoretical analysis of forward link in a CDMA cellular system by introducing the τ -th power of distance driven control strategy. Based on the power control, the capacity and outage probability of the system are estimated and discussed. In particular, we consider the impact of fading environments and investigate the “hole” phenomenon. Based on our numerical results, the “hole” points are at the upper bounds of where it is possible to ensure minimization of the maximum value of total Interferenceto-Signal Ratio (ISR) [4]. At those upper bound points, at least, the power control strategy leads to approximately threefold the capacity compared to the case without power control strategy. It can be concluded that the forward link without power control strategy is a very heavy restriction for the capacity of the CDMA system, especially in environments of significant fading.

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