The Heterogeneous Network (HetNet) has emerged as one of the most promising developments toward achieving the target of the Long Term Evolution-Advanced (LTE-A) systems. However, Co-Channel Interference (CCI) is one of the critical challenges of HetNet, that degrades the overall performance of a system. Therefore, an appropriate Radio Resource Management (RRM) mechanism is required to deploy and expand the HetNets properly. In this paper, a new RRM strategy called Fractional Frequency Reuse with Three Sectors and Three Layers (FFR-3SL) technique is proposed. The FFR-3SL efficiently utilizes the radio resources and alleviates the effects of CCI in LTE-A HetNets and thereby improving the system performance. In order to implement the proposed strategy, the entire macrocell coverage area is segmented into three sectors and three layers, while the total bandwidth is divided into seven subbands. Subsequently, the subbands are accurately distributed among femtocells and macrocells by employing the proposed algorithm. As a result, the co-tier and cross-tier interferences are managed on a prior basis. The Monte Carlo simulation is performed to evaluate and compare the performance of the proposed method with the existing methods. The simulation results show that the proposed method achieves higher throughput and better capacity in LTE-A HetNet system. Furthermore, the efficiency of the system is improved with regard to user satisfaction in terms of signal to interference and noise ratio (SINR) values.