Study and implementation of an iterative decoder for SFBC-OFDM systems with imperfect channel knowledge

In this paper, we consider the problem of the Space Frequency Block Codes (SFBC) decoding, according to the Maximum A Posteriori (MAP) criterion when the channel is not perfectly known at the receiver. We propose to use the Expectation Maximization (EM) algorithm to solve this problem. Simulation results show that the performance of our iterative decoder using the EM algorithm is very close to the performance obtained when the channel is perfectly known. We also propose an efficient implementation of the iterative decoder (based on the EM algorithm) on FPGA.