Load Balancing And Interference Management For D2D-Based Relay Communications In Heterogeneous Network

As smart devices spread, the demand of access and the requirement of the quality of service(QoS) grew explosively. Accommodating more users and improving the performance of the overall network based on existing network architecture while meeting the QoS of the pre-existing users become the primary requirements. The heterogeneous network(HetNet) has been proposed to accommodate more users with spectrum resources reusing and device to device(D2D) communication offloads the traffic at the base station by direct communication between two end devices in proximity. In this paper, we combine these two new technologies, and propose load balancing strategies for D2D-based relay communications to improve the performance of the HetNet. In this paper, our study mainly includes the following contents.First, for the ubiquitous load imbalance problem between the cross-tiers in the HetNet, we propose an algorithm that takes the resource management with transmission power control into account and study the maximum transmission rate problem based on D2 D communications in self-organized HetNet. Users could send data to an adjacent uncongested femtocell through the D2D-based relay communications rather than wait for the response from the congested macrocell. The simulation results show that with the guarantee of the performance of the pre-existing users, the heterogeneous network can accommodate more users and higher throughput can be achieved, thus the performance is significantly improved.Second, we propose an energy efficient load balancing strategy for D2D-based relay communications with fair capacity usage of the femtocells for the load imbalance problem between the co-tiers of the femtocells. We solve the maximum transmission rate problem by the femtocell resource participating based on graph coloring, fair usage of the femtocells, energy efficiency relay node selection and the interference management under g-ALA control scheme. Simulation results show that, with the guarantee of the performance of the pre-existing users, the heterogeneous network can accommodate more users and eventually achieve a higher throughput and better energy efficiency than that proposed without considering the fair capacity usage of the femtocells, thus the performance is significantly improved.