Doubly Iterative Receiver for Single carrier Cyclic-Prefix Transmissions with EM-Based Channel Estimation

Single carrier cyclic-prefix (SCCP) transmission is the scheme that can support the increasing demand of nowadays high data rate applications. The block iterative generalized decision feedback equalizer (BI-GDFE) is an iterative and effective interference cancellation scheme which has near-ML performance yet with very low complexity. In order to deploy this scheme, the channel state information (CSI) must be available at the receiver. In this paper, the problem of channel estimation using the expectation maximization (EM) algorithm is investigated. The BI-GDFE provides the soft information of the transmitted signal for the EM-based algorithm. The resulted receiver becomes a doubly iterative scheme. To evaluate the performance of the proposed estimation algorithm, the Cramer-Rao lower bound (CRLB) is also derived. Computer simulations show that the bit error rate (BER) performance of the proposed receiver can reach the performance of BI-GDFE with perfect CSI.