Combined selection of users and antennas during coordinated precoding of base station

In the coordinated precoding of base station, the number of supported users is commonly limited by that of antennas, so that a selection of users is required. In addition, for the purpose of further reducing the interference to other users, a selection of antennas can also be performed. Based on the two above-mentioned details, two low-complexity and near-optimal combined selection algorithms of users and antennas in base-station coordinated systems are proposed to maximize the system sum capacity. The two algorithms, respectively based on capacity and norm, both adopt the greedy principle to simultaneously select users and antennas. Simulated results show that, when the number of users in the system approaches the precoding constraints, only the antenna selection can be used, and the system performance is even better than that before the antenna selection; and that, when there exist a great number of users in the system, the combined selection can be used, which may achieve multi-user diversity gain resulting from user selection as well as additional performance gain for the users without antenna selection but with the same antenna number.