AN efficient RAKE-CFAR method for downlink mobile positioning in UMTS FDD mode.

This paper deals with position location (PL) problem in the context of wideband code division multiple access (WCDMA) mode of UMTS systems using the time of arrival (TOA) in the downlink (DL) scenario. We propose to use a RAKE receiver in conjunction with a constant false alarm rate (CFAR) detector in order to optimally detect the first arriving path. An improved version is also considered using subspace projection and/or high resolution TOA estimation technique. The proposed method allows us to obtain a good estimation of the far-located BS´s time of arrival (TOA) and hence, it represents a good solution to the hearability problem. Realistic simulations show the accuracy improvement provided by the proposed detector over a simple RAKE receiver.