Cramer–Rao bounds for channel estimation in UWB impulse radio

This paper addresses the Cramer–Rao bound (CRB) calculation for channel parameter estimation in impulse radio ultra-wide band systems. We consider a time-hopping code scheme with binary pulse position and pulse amplitude modulation formats. We first derive in closed-form the (resp. modified) CRB for the multipath channel parameters in the data-aided (resp. non-data-aided) context. Unlike existing methods, the calculations are derived taking into account the overlapping between signal echoes due to multipaths. We illustrate the benefit of taking into account the overlapping assumption on realistic channel propagation environment. Simulations show that the CRB using the non-overlapping assumption clearly overestimate the performance.