Distributed power control with active cell protection in future cellular systems

Distributed power control schemes have been intensively studied in the literature for uplink transmissions in cellular networks as well as in ad hoc networks. In the schemes with active link protection, the signal to interference plus noise (SINR) requirements of the new users are gradually approached without violating the existing links. In this paper, we consider a downlink cellular scenario, in which new nomadic cells seek admission to the network. A distributed power control algorithm with active cell protection is presented, where a cell is said to be active if it has sufficient resources to support the connected users and, otherwise, it is said to be inactive. With the proposed algorithm, inactive cells lower their loads by gradually performing power ramping, while active cells scale their transmission power accordingly, to avoid being overloaded. We prove the active cell protection property and compare the convergence of the algorithm under different interference assumptions. Further, we present an algorithm for adapting the power ramping factor in power limited scenarios for further performance enhancements.