Power and data rate assignment for maximal weighted throughput in 3G CDMA: a global solution with two classes of users

Relevant to the uplink of a VSG-CDMA system, a technique part of 3G standards, this work investigates power and data rate allocations that maximize the network weighted throughput. Each terminal has one of 2 possible weights, which admit various practical interpretations. Earlier works of ours tell us that at least one terminal should operate at the highest available data rate, and that terminals not operating at this rate should operate at the same signal-to-interference ratio (SIR). We have also learned that when only two terminals of dissimilar weights operate at maximal data rate, the optimal SIR values for these terminals is obtained as an intersection point between an "X-shaped" graph arising from optimality conditions, and a "U-shaped" graph arising from the feasibility condition on power ratios. In the present work, we introduce a general procedure to seek an allocation that is a global optimizer. The analysis is based on classical optimization theory, and should accommodate a wide variety of physical layer configurations.