Power Allocation for Maximizing the Minimum Rate With QoS Constraints

Max-min fair power allocation brings higher average throughput and better utilization of the resources than a work-conserving equal-sharing policy. In this paper, instead of achieving a common maximum sum-rate objective, an optimal power-allocation design for maximizing the minimum rate of the reverse link of code-division multiple-access (CDMA) systems with quality-of-service (QoS) constraints is investigated. To avoid the difficulty of directly solving a nonconvex optimization problem, we split the original problem into two successive steps. First, we try to derive the structure of the optimum solution via majorization theory. Then, based on this result, we propose a very efficient search method to find the max-min fair solution, which reduces the search space from a 1-D space into a finite set of points. Compared with existing methods, a much lighter computational complexity is required by our method.