EXIT chart analysis of BICM-ID based receiver for shallow underwater acoustic communications

We present extrinsic information transfer (EXIT) chart analysis of iterative equalizer implemented using adaptive decision feedback equalizers (DFE) and bit-interleaved coded modulation with iterative decoding (BICM-ID) to analyse the performance. It is shown from the EXIT chart analysis that the performance of the BICM-ID based receiver strongly depends on the ability of the equalizer to remove the intersymbol interference (ISI) and the number of taps employed in the feedback filter of the DFE. It is demonstrated that error free communication can be achieved even though the DFE does not cover the entire span of the channel, which is typically the case for underwater communications (UWC). Furthermore, it is shown that the latency associated with the iterative processing can be avoided if the initial equalization is successful, leading the receiver to iterate for less iterations.