Load balancing for D2D-based relay communications in heterogeneous network

To increase the number of accommodated users in the cellular heterogeneous network (HetNet), we propose an energy efficient load balancing strategy for device-to-device (D2D) based relay communications. In a HetNet, user could sent data to an adjacent uncongested femtocell through the D2D-based relay communications rather than wait for the response from the congested macrocell. Specifically, the proposed strategy manages resources by taking into account both the cross-tier and the co-tier interference, and solves the maximum transmission rate problem based on D2D communications in heterogeneous network. 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, thus the performance is significantly improved.