Iterative Channel Estimation for Nonbinary LDPC-Coded OFDM Signals

This work deals with the issue of channel estimation in the context of non-binary LDPC-codedOFDM systems over doubly selective multipath channels. In particular, we show how to derive aniterative Wiener-filter-based estimation method using both time and frequency channel correlation andconsidering the particular characteristics of the channel code. The proposed algorithm can use eithersoft information or hard decisions fed back by the decoder to refine the channel estimation, so as toimprove the system performance at the expense of an increased receiver complexity. Simulation resultsunder typical working conditions are presented to compare the performance of the proposed methodwith respect to classical techniques.