A maximum-likelihood decoder for joint pulse position and amplitude modulations

In this paper, we consider the problem of Maximum-Likelihood (ML) detection with multi-antenna Impulse Radio Ultra-Wideband (IR-UWB) communications in the cases where the information is modulated onto either the positions or the positions and amplitudes of the transmitted UWB pulses. The proposed solution assures good convergence times since the structure of these sparse and multi-dimensional constellations is taken into consideration. While all the known ML decoders can not be applied with these constellations that do not have a lattice structure, the proposed solution assures an optimal detection.