The Directional Relay (DR) scheme-aided LTE-A communication systems

We propose the use of relay terminals at the cell edge of an LTE-based cellar system. Each relay terminal is equipped with a 120° directional antenna. We refer to this scheme as the Directional-Relay (DR) scheme. The DR scheme coordinates the inter-cell interference (ICI) stemming from adjacent cells and increases the desired signal level at cell-edge regions. To validate the performance of the DR scheme, we derive the average signal-to-interference plus noise ratio (SINR) and the average capacity and compare it with the conventional universal frequency reuse factor (UFRF). The results show that the proposed DR scheme provides higher average SINR and average capacity compared to the UFRF due to the assistance of the distributed relay nodes.