A method for estimating one or more parameters of a ultra wideband signal and a receiver system for receiving ultra wideband signals is provided. The method for estimating one or more parameters of a signal in an ultra wide band system including estimating the parameter(s) for a first signal element in a received signal then removing this signal element from the signal to obtain a modified signal. The parameter(s) for a number of further signal elements are then estimated and these elements are removed from the modified signal to form a refined signal. The parameter(s) for the first signal element are re-estimated to re-define the first signal element based on the refined signal minus the signal element having the greatest amplitude. The parameter(s) for the signal element having the greatest amplitude are re-estimated to re-define this signal element. The steps are repeated to generate a refined estimate of the parameter(s) for the first signal element. There is also disclosed a receiver for performing the above steps.