A novel cell selection method for LTE HetNet

In LTE-A system, heterogeneous network (HetNet) consisting of macro nodes and low power nodes such as pico nodes, femto nodes and relay nodes are deployed along with traditional macro only deployment to improve the system capacity. We have to balance the load between macro and low power nodes to improve the system performance. Cell selection plays an important role in balancing the system load and thus overall performance of the system. RSRP and CRE are the two conventional cell selection methods employed in LTE Hetnet. In RSRP method most of the UEs will select high power macro cell. This can limit the cell splitting gain. An alternative to this is to increase the range of pico cell by adding a bias to the Reference signal received power (RSRP) from the pico cell (Cell Range Expansion (CER) method). This cause UEs within the Range Expansion (RE) region to get attached to pico cell without considering the capacity of the pico cell, which will reduce the system performance. This paper propose a new cell selection method called Network coordinated cell selection (NC) which allow a UE within the RE region to be offloaded to pico cell based on the load of the pico cell and the achievable throughput. Simulation results shows that this method can achieve better performance than conventional cell selection methods.