Joint channel and time delay estimation for LTE positioning reference signals

The ranging performance of the Long Term Evolution (LTE) positioning reference signal (PRS) is enhanced with respect to traditional correlation-based approaches in multipath channels. For that purpose, a joint maximum likelihood (ML) channel and time delay estimation is introduced for the PRS signal. The estimation can be implemented by using the least-squares (LS) criterion that benefits from the multicarrier flexible waveform. Preliminary results are shown with a comparison of the root-mean-square error (RMSE) of this ML estimator and the corresponding Cramér-Rao Bound (CRB) expression for a specific urban pedestrian channel model.