Research On Interference Suppression Technology For Femtocell

There lies a challenge to implement higher standards of capacity and coverage quality for wireless communication systems as the number of users and their demand for high-rate services increase rapidly. According to recent surveys, around 70% of the data services take place in indoor environments. However, indoor signal reception is poor caused by severe penetration losses through walls.Femtocell, as a method to improve indoor coverage efficiently, is proposed into 3G and IMT-A systems and researched extensively. On the other hand, femtocell is installed by subscriber personally without prior network planning. And it will induce very complex interference situations with the existing macrocell networks.In this paper, the interference scenarios of femtocell and macrocell network co-existence are researched. We analyze main interference scenarios and key factors which affect the femtocell coverage and interference and give related simulations. On the base of that, we propose an interference suppression solution for femtocell, using dynamic frequency reuse and distributed power control, which can comprehensive resolve the interference problem. Furthermore, a distributed uplink power control algorithm for femtocell based on game theory is proposed. It optimizes the uplink system total capacity utilizing the price factor. Simulation results show that the proposed algorithm converges faster and needs little number of iterations, which let femtocell adapt to the domestic wireless environment quickly.