Improved distributed power control algorithms with gradual removal in wireless networks

In the well-known distributed target-SIR tracking power control algorithm, when the target-SIR requirements are not reachable for all users (due to heavy load and/or deep fading), some users transmit at maximum power without reaching their target SIR. Such users inefficiently consume their energies, and introduce unnecessary interference to others, which in turn results in more unnecessary non-supported users. To alleviate the situation, a minimal number of users have to be removed (the gradual removal problem). In this paper, we propose improvements to two algorithms that were shown to be the best of the existing distributed power control algorithms for the gradual removal problem, and demonstrate that the improved algorithms have smaller outage probabilities. In addition, we show that the convergence rate for one of our improved algorithms is substantially better than those of both original algorithms.