Under Feedback and Interference Constraints Uplink Power Control in Two-Tier Networks

This paper considers optimum uplink power control policy that maximizes total sum-rate without any interference cancellation techniques under interference and feedback constraints at next generation communication systems. System model has two tier and it is assumed that the feedback channel between these tiers has finite capacity. Second tier users (STU) cause interference on first tier users (FTU) and base station (FTB) while communicating with second tier base station (STB). In proposed scenario, this interference power on first tier network is limited at a certain level. To this end, two different feedback policies are proposed. The first one is determining the K smallest interference channel coefficients of STUs by FTU and sending them to STB. The other policy is that STB requests the interference channel information of K users that have the best direct channel state from FTB. Due to proposed scenario is not a convex problem, it is solved with DC programming well-studied in literature before and performances of proposed feedback policies are compared.