Wideband interference suppression in turbo-coded DS/FH system

The performance of two previously proposed interference suppression schemes in a turbo-coded hybrid direct sequence/frequency hopping (DS/FH) system, with the presence of broadband interference, is presented. The analysed schemes are the ξ-filter and polar suppressor, proposed for cancelling interfering signals that can vary from narrowband to wideband, with the bandwidth comparable to that of the desired direct sequence (DS) signal. The classical coding approach is compared to a data-aided approach, where the desired signal estimates are used in the suppression block, with an idea to make the suppression procedure more efficient. Performance comparisons of systems that use reencoding to produce feedback information with the system without reencoding show that an improvement can be obtained in the latter case. Both cases, however, do not show a significant improvement over the classical approach