EM Based Iterative Receiver for Joint Decoding and Channel Parameter Estimation in Space-Frequency Turbo Coded OFDM

Expectation-maximization (EM) based joint decoding and channel parameter estimation for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system is considered. A new iterative receiver structure is proposed to operate together with space-frequency turbo coded modulation (SFTuCM) using decoder outputs to refine the channel parameter estimates. The proposed receiver performs well with low pilot overhead despite the fast changing channel state. The proposed receiver improves not only the error probability performance but remarkable improvement is achieved in the channel parameter estimation accuracy when compared to pilot based estimation with the same overhead