Simultaneous routing and power allocation in CDMA wireless data networks

In CDMA wireless networks the optimal routing of data depends on the link capacities which, in turn, are determined by the allocation of transmit powers to the links. The optimal performance of the network can only be achieved by simultaneous optimization of routing and power allocation. In this paper, we study this joint optimization problem in CDMA data networks using convex optimization techniques. Although link capacity constraints of CDMA systems are not jointly convex in rates and powers, we show that by using coordinate projections or transformations, the simultaneous routing and power allocation problem can still be formulated as (in systems with interference cancellation) or approximated by (in systems without interference cancellation) a convex optimization problem which can be solved very efficiently. We also propose a heuristic link-removal procedure based on the convex approximation to further improve the system performance.