Iterative decoding of product block codes based on the least mean square error criterion

A soft-input soft-output decoder based on the least mean square error (LMSE) criterion is presented and employed for iterative decoding of product codes. The residual estimation error is derived and used for analyzing the convergence of the iterative process as well as a stopping criterion. A relation between the LMSE and the MAP decoders is also established. Simulation results are presented for several codes revealing near-optimal performance.