SAGE Based Suboptimal Receiver for Downlink MC-CDMA Systems

An iterative joint data detection and channel estimation algorithm for downlink multi-carrier code division multiple access (MC-CDMA) systems is proposed. The resulting algorithm is a space alternating generalized expectation-maximization (SAGE) algorithm which updates the data sequences serially and the channel parameters in parallel, leading to a receiver structure that also incorparates interchannel interference cancellation. Its performance is compared with various Minimum Mean Square Error (MMSE) estimators for a multipath frequency selective fading channel using simulations. It is illustrated that the proposed SAGE algorithm performs better than the MMSE estimators considered in this paper.