Research Information System
Presentation, pp.1-90, 2020
With the emergence of new generation wireless networks, the number of wireless subscribers and demand for different services along with high data rates provided by them are increasing exponentially each day. Such an increase, however, requires efficient utilization of radio resources in these networks, especially in Heterogeneous Networks (HetNets) which is one of the target specifications of Long Term Evolution Advanced (LTE-A) wireless networks. A HetNet is a multi-tier cellular wireless network including macrocells, microcells, picocells, and femtocells, and the network traffic is shared by these cells according to some optimization criteria, policy, etc. Though, one of the critical challenges for HetNets is the efficient utilization of radio resources in such an interference limited environment. Recently, Fractional Frequency Reuse (FFR) methods have appeared as one of the prominent Radio Resource Management (RRM) techniques for LTE-A HetNets to mitigate co-tier and cross-tier interferences and to increase system throughput. However, in order to efficiently use radio resources and to achieve higher throughput and better spectral efficiency in LTE-A HetNets, there is still a need for new RRM techniques. In this thesis, we propose a novel RRM technique for LTE-A HetNets, referred to as FFR with Three Sectors and Three Layers (FFR-3SL). In the proposed FFR-3SL method, the entire macrocell coverage area is split into three layers as central, middle and outer layers and three sectors. On the other hand, the total available bandwidth is divided into seven subbands such as A, B, C, D, E, F, and G. The subband ’G’ is allocated to the macro users in the zones of central layer while the remaining six subbands are shared among the macro users and femto users in their respective zones. As a result, co-tier and cross-tier interferences are managed on a prior basis. Simulations are performed to evaluate the performance of the FFR-3SL method in terms of system throughput, spectral efficiency, and user satisfaction, etc. The performance of the proposed FFR-3SL method is also compared with the existing FFR methods in the literature. The results show that the proposed method achieves higher throughput and better spectral efficiency as compared to existing methods. Furthermore, the efficiency of the system is improved with regard to user satisfaction in terms of signal to interference and noise ratio (SINR) values. In this thesis, the effects of user location distribution (ULD) and the user densities in central, middle and outer layers on FFR-3SL method are also investigated. Modified FFR-3SL method is presented under these conditions.