SC-FDE (single-carrier with frequency-domain equalization) together with soft packet combining ARQ techniques (automatic repeat request) was shown to be effective for broadband wireless systems with deep fading effects such as those inherent to shadowing. However, they are not suitable to cope with strong interference effects, especially when the channel remains fixed. In this paper, we consider UWB (ultra wide band) systems employing SC-FDE techniques in the presence of strong interference signals that occupy a significant part of the transmission band and we propose suitable soft combining ARQ schemes. Our techniques are able to cope with strong interference levels as well as deep fading, even for fixed channels.