A New SAGE-Based Receiver for MC-CDMA Communication Systems

Multicarrier code division multiple access (MC-CDMA) systems have arrested a lot of attention, owing to the simple implementation and powerful resistance to frequency-selective channels and the CDMA with the suitability for multiuser systems. Although MC-CDMA systems spread symbols using orthogonal codes to ensure orthogonality, orthogonality may be destroyed at the receiver due to frequency selective fading and then results in multiple access interference (MAI) and inter-carrier interference (ICI). The space-alternating generalized expectation–maximization (SAGE) algorithm is with high convergence speed and performs maximum-likelihood estimation/detection of the transmitted signals. For MC-CDMA systems, existing SAGE algorithm is used to cancel the ICI (Panayirci et al. in IEEE Trans Signal Process 58(8): 4225–4238, 2010), or to cancel the MAI (Panayirci et al. in 16th IST Mobile and Wireless Communications Summit, 2007). In this paper, the proposed interference cancellation scheme not only performs MAI cancellation but also performs ICI cancellation for the MC-CDMA systems. Some simulation examples are given to show the effectiveness and comparisons of the proposed receiver.