LTE system level performance in the presence of CQI feedback uplink delay and mobility

Long Term Evolution (LTE) is a promising technology for the wireless and mobile communication systems and is being commercially launched in various countries of the world. The Third Generation of Partnership Project (3GPP), through design and optimisation of new radio access techniques, is further developing the future LTE-Advanced technology to remain on the forefront of wireless technologies. However, it is still challenging in LTE to provide the desired quality of service to the users particularly in the presence of high mobility and uplink feedback delay. In this paper, the impact of Channel Quality Indicator (CQI) uplink feedback delay on the overall network performance under different scheduling algorithms and mobility patterns is discussed. We study average user equipment (UE) throughput, average cell-edge UE throughput and average cell throughput under mobility and conclude that for an efficient LTE-Advanced scheduling algorithm, UE speed and CQI feedback delay must be taken into account.