Maximum Likelihood time of arrival estimation for ultrawideband signals

In this contribution, we investigate maximum likelihood (ML) techniques for the estimation of time of arrival (ToA) for ultrawideband (UWB) propagation signals. Using the same methodology as [1], which was introduced for the multichannel estimation, we derive the ML criteria for the UWB ToA parameters estimation and we apply a denoising frequency-domain procedure so that the ML cost function becomes asymptotically noiseless. We show how the pseudo-quadratic ML (PQML), which is naturally asymptotically denoised, can be applied in the case of UWB time delays estimation and prove its convergence to the ML minimizer. Since the evaluation of the first time delay estimate can be converted to a distance estimate, the proposed method can be used for UWB ranging purposes and its optimal performance will hence follow for the UWB ranging accuracy. Simulation results are presented to demonstrate the good performance of the proposed techniques.