A proposed efficiency metric for LTE-advanced carrier aggregation

Abstract

LTE-Advanced uses Carrier Aggregation (CA) and Spatial Multiplexing (SM) Multiple Input Multiple Output (MIMO) antenna system to achieve the target data rates of the 4G and 5G cellular system. Therefore, this paper studies the performance of the concurrent operation of the inter-band CA and SM MIMO and proposes a novel CA efficiency metric that integrates the performance of different Component Carriers (CCs) into a single parameter. The proposed CA metric is then used to recommend a CA scenario that balances the transmit power of the CCs and results in efficient utilization of the antenna resources. The study is performed for many eNodeB-UE links in an urban environment at CCs of 800 MHz and 2.6 GHz considering different combinations of single and multiple-antenna systems. The radio channel is modelled using an urban site-specific 3D ray-tracing tool combined with measured antenna 3D radiation patterns. The simulation results show dependency on the number of aggregated spatial streams and cell radius. The paper recommends (1) the use of higher number of spatial streams for the lowest CC, (2) cell radius less than 600 m. The proposed CA efficiency metric can be used for system level simulation studies of any wireless technology that supports CA.