Cognitive based dynamic soft frequency reuse for LTE downlink system

Cognitive Radio (CR) has been widely discussed as its mechanisms and methodologies can remarkably enable dynamic and efficient use of scarce spectrum resource. This paper focuses on the performance improvement of cell edge users via introducing cognitive idea into LTE cellular networks. By exploiting inter base station cooperation, a cognitive based dynamic soft frequency reuse (C-DSFR) scheme is proposed. With C-DSFR, spectrum usage status and co-channel interference from adjacent cells are exploited to implement opportunistic spectrum access and service base station selection for cell edge users who, in most proposed strategies such as soft frequency reuse (SFR), usually executes the spectrum allocation in a relatively static way probably resulting in imbalanced spectrum efficiency in cell center and edge area. Simulation results show that enhanced spectrum efficiency is achieved and transmission rate of cell edge users is significantly improved with the proposed C-DSFR.