Uplink power control, subcarrier allocation and beamforming in coordinated multicell systems

We propose a joint bit and power loading, beamforming, multiple base station set (MBS) selection and subcarrier allocation algorithm for a resource allocation problem in a uplink multicell coordinated multi-basestation reception system. The objective is to minimize the total transmit power with rate constraint per mobile station (MS). The resources that we are considering include power, subcarrier, beamforming and the MBS set. The algorithm iteratively loads bits to the best link and subcarrier for the current rate increment and updates the signal-to-interference-plus-noise ratio (SINR) targets of all MSs on that particular subcarrier. Given a fixed rate target per subcarriers, the algorithm gives the optimal solution, i.e, optimal power vector, beamforming vector and MBS set. The iteration continues until all MSs reach their rate targets. We also propose a simplified scheme of such an algorithm. The simulation results show that the proposed algorithms perform significantly better than the simple approach without considering subcarrier allocation, i.e., equal rate allocation over the frequency spectrum, especially in a strong interference limited scenario.