Energy Optimization in Dense OFDM Networks

Network densification is a promising technology to increase 5G system capacity. Energy saving and resource utility are the key issues for the densified OFDM systems. In contrast with the conventional energy optimization problem for MIMO-OFDM system, we use a more realistic model for SINR by considering the load factor of OFDM systems, which makes the energy optimization problem very difficult to solve. First, we show that for single-antenna scenario, this problem can be transformed into a convex problem, which can be solved more efficiently comparing with the existing methods. Next, for the more complex multiple-antenna scenario, we derive a successively convex program method to obtain the KKT point of this problem. Simulation shows the effectiveness of the proposed method.