In this contribution we study and compare the performance of orthogonal frequency code division multiplexing (OFCDM) and multi-carrier direct-sequence code division multiple access (MC-DS-CDMA) based on MMSE multi-user detection (MUD) in single-cell and multi-cell environments for the forward link of a cellular mobile system. The BER and PER results for both systems show that the effect of user loading and modulation scheme on each system varies the performance significantly while changing the spreading factor has no noticeable impact on both system performances.