Abstract:

In the two-tier network constituted by femtocell and macrocell, interference problems are highlighted, traditional studies focused on the static allocation of resources, which have failed to improve the spectrum resources utilization effectively. A spectrum sensing technology in cognitive radio is used to detect the empty spectrum resources to allocate to the femtocell . A cooperative spectrum sensing model of the multi-user multi-antennas femtocell system is given, the global detection probability is derived. Under the premise of a given probability of false alarm, a particle swarm optimization algorithm in fusion center is used to optimize the weight allocated to each femtocell user’s sensing information, which can maximize the global detection probability of the system and improve the utilization of spectrum resources. Simulation results show that the proposed algorithm can effectively improve the detection performance of the system, has better realtime and can be used for the actual two-tier network communication system.