Turbo Equalization of Coded OFDM Symbols in Poor HF Channels

In this paper, an iterative receiver that utilizes soft outputs of a FEC decoder to improve channel estimates iteratively is proposed. At each iteration, reliable symbols are selected and included in the extended training set. The channel is re-estimated using the extended set at successive iterations. The performance of the proposed technique is tested in simulated poor HF channels and shown to improve the performance by about 2 dB at a BER of 10
^-4
over the non-iterative case