DEVICE AND METHOD FOR ESTIMATING DOPPLER SPREAD IN A MOBILE COMMUNICATIONS TERMINAL

摘要

The invention is suitable for use in an OFDM system, such as the 3GPP-LTE mobile phone system. A method of estimating Doppler spread in a mobile communications device includes: (a) selecting a channel estimate from each of a sequence of time slots at each of a series of selected sub-carrier frequencies; (b) performing a Digital Fourier Transform (DFT) on the selected channel estimates at each selected sub-carrier frequency to thereby compute DFT components at different frequency bins; (c) summing the DFT components at all selected sub-carrier frequencies for each different frequency bin; (d) detecting the frequency bin at which the summed DFT components first falls below a predetermined threshold; and (e) converting the detected frequency bin into a Doppler spread estimate.