Ultra-wideband (UWB) transmission is a promising technology for future high speed wireless networks. In this paper, we propose a novel signal detection approach with noise suppression for UWB systems. This approach is based on an overcomplete dictionary signal representation and a sparsity-driven optimization algorithm. We introduce general approaches for UWB signal detection, and present guidelines to generate overcomplete dictionaries for signals in noise. UWB signal detection is achieved by solving an l1 norm minimization problem, which can be solved using low complexity linear programming algorithms. Examples are given to demonstrate the performance of the proposed approach