AMBIGUITY RESOLUTION IN POSITIONING MEASUREMENTS

摘要

A computer implemented method of providing Reference Signal Time Difference (RSTD) data comprising receiving an uncertainty window centred around an expected RSTD value and determining the Power Delay Profile (PDP) of each OFDM Positioning Reference Symbol (PRS) symbol within the uncertainty window. The PDP is obtained by performing an FFT on the received PRS, coherently combining two successive FFT outputs (for catching a whole PRS signal if not aligned with the UE FFT window), and then performing the IFFT on these combined FFTs to get the PDP. Non-coherent combining after the IFFT can be alternatively done. By combining the FFTs, an ambiguity arises on the potential RSTD (like for aliasing) which is solved by using non-combined previous or succeeding PDPs.