An Enhanced Cognitive Femtocell Approach for Co-Channel Downlink Interference Avoidance

The deployment of low-power nodes such as femtocells within the macrocell's coverage area is one of the main features of future 5G networks. However, challenges arise in the femtocell planning and management, particularly due to interference occuring when femtocells are deployed in a co-channel with the macrocell. The cognitive radio inspired femtocell is one of the solutions to mitigate interference. In this study, the cognitive scheme is enhanced by enabling the femtocell to take advantage of LTE channel-dependent scheduling in order to predict the future resources of nearby victim macro- users and avoid using them. Simulation results show that the co-channel interference on the macrocell downlink signal is minimal, and therefore performance is improved under the condition that the cognitive femtocell operates adaptively and monitors spectrum allocations continuously.