Interference mitigation techniques for femtocell networks

In femtocell networks, low-cost and low-power femto base stations are overlaid on macro cellular systems, and thereby interference between the femtocell to the macrocell becomes a major obstacle. In this paper, we propose a distributed beamforming technique to efficiently mitigate the interference for downlink multi-input single-output femtocell networks. First, a beamforming structure for femtocell is presented, and then the beamforming vector is optimized based on Karush-Kuhn-Tucker conditions. Simulation resuslts demonstrate that the proposed method show almost the same performance compared to conventional method with significantly reduced complexity.