Sum Power Minimization Under Rate Constraints in Multiuser OFDM Systems

For a multi-cell system using OFDM, this paper considers the multiuser power control problem in a frequency-selective interference channel. In particular, the aim of this work is to develop an iterative algorithm for user power control and bit loading on OFDM subcarriers, which minimizes the sum power under a constraint on the user bit rates. The performance of the proposed algorithm is compared against two previous algorithms in terms of sum power, probability of convergence within a fixed number of iterations, and mean number of iterations required for convergence.