Future wireless communications systems should be able to accommodate the large number of users and fulfill their diverse quality-of-service requirements. It is widely reported that current wireless systems cannot afford the expected high demands in the data rates. Therefore, innovative physical-layer solutions should be proposed to overcome such a challenge. In this paper, an integrated system architecture for multi-user scenarios is presented. The proposed architecture combines promising techniques to leverage their outstanding overall performance. Specifically, the proposed architecture combines code division multiple access, space time block coding based orthogonal frequency division multiplexing and spatial modulation in an integrated system whose overall performance is shown to outperform state-of- the-art alternatives.