Institute of Electrical & Electronic Engineers
Future cellular wireless networks based on MIMOOFDM enable high data rates in outdoor scenarios. Limitations in coverage, especially at cell-edge, might be overcome by transmission over relays, which are therefore widely discussed for LTE-Advanced networks. Here, a multi-hop relay node is placed at the cell-edge or in a coverage hole in order to compensate for the penetration path loss caused by buildings. Relay nodes can be deployed in two modes, either as amplify and forward or as decode and forward relay. The later system may benefit from independent link adaptation which is a key concept especially under fading conditions in outdoor broadband wireless. This paper reports on first multi-hop relaying field trials in the LTE downlink.