An Iterative Receiver Design Using a SAGE Based List Detector in Turbo Coded OFDM

Abstract

An iterative receiver design using a space-alternating generalized expectation-maximization (SAGE) based list detection and channel estimation for a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system is considered. A new SAGE based list detection algorithm is proposed to operate as a receiver front-end to approximate the MAP algorithm with reduced complexity and with minor losses in the performance. The receiver front-end, a decoder, and a channel estimator constitute an iterative receiver to jointly decode the transmitted bits and to estimate the channel state. The proposed receiver front-end shows a good performance when compared to the other MAP approximation, i.e., to the K-best list sphere detector (LSD) and a linear front-end. Furthermore, the whole iterative receiver performs well with the low pilot overhead despite the fast fading channel.