Lähetkangas, Eeva; Pajukoski, Kari; Tiirola, Esa (Radio Research, Nokia Siemens Networks, Oulu, Finland)
Hämäläinen, Jyri; Zheng, Zhong (Department of Communications and Networking, Aalto University School of Electrical Engineering, Aalto, Finland)
Standardization of 3GPP LTE-Advanced (LTE-A), also called as 4G, is continuing strongly. Yet, in parallel the discussion on performance targets for systems beyond 4G have been initiated in industry. The aim of this paper is to investigate the link level performance of LTE-A downlink (DL) when large antenna array MIMO is employed. The link level simulation results show very high user throughputs when employing e.g. 8x8 MIMO. Yet, the comparison between simulation results and known spectral efficiency bounds show that LTE-A performance is still quite far away from theoretical limits. Results also indicate that realistic beyond 4G peak rate target on link level can be set close to 10 Gbps provided that 8x8 MIMO and 256QAM are applied, and the operation bandwidth can be doubled from current 100MHz. The spatial correlation in both transmitter and receiver ends will reduce the performance.