In this paper, we propose a hybrid multiple access scheme which combines interleave division multiple access (IDMA) and code division multiple access (CDMA), therefore, we refer to this scheme as IDMA/CDMA. We employ IDMA technique as the uplink transmission and CDMA technique as the downlink transmission. Thus, IDMA/CDMA can achieve a very simple chip-by-chip iterative multi-user detection (MUD) strategy at the base station, and the simplified receive processing for the user ends (UEs). The proposed scheme can substantially utilize the advantages of IDMA and CDMA technologies.