In this paper, we introduce a simple but efficient multi-user relaying scheme for the uplink of dual-hop wireless access networks employing Decode & Forward relays. This scheme is further combined with cooperative multi-user detection. The link level simulation results obtained for a system based on IEEE 802.16e standard specifications reveal that the proposed scheme yields significant performance gains compared with the cases that (a) conventional multi-user detection is applied instead and (b) the equivalent single-user relaying scheme is employed.