Abstract— Ultra wide band (UWB) impulse radio (IR) technology calls for robust and low-complexity receiver techniques. State-of-the-art proposals are both coherent ML receivers, noncoherent transmitted reference systems, or hybrid choices, all of which are derived from an AWGN model. In this paper we investigate an alternative technique which has been recently proposed, and which is based upon a Gaussian mixture (GM) model for multiple access interference. We show that this technique exhibits superior performance in comparison to AWGN receivers, and can be implemented with low-complexity.