Patent ID: 8442134
Filing Date: 2013-05-14
Classification: H04L

Abstract:
1. A method for time synchronization tracking in an orthogonal frequency division multiplexing (OFDM) receiver, the method comprising: obtaining a discrete Fourier transformation (DFT) output vector; determining a sample timing offset indication using reference symbols that are extracted from the obtained DFT output vector; and adapting an OFDM symbol timing using said determined sample timing offset indication, wherein said determining step further comprises: (a) estimating a channel transfer function at equidistant frequency positions using said reference symbols, for a first OFDM symbol; (b) determining a plurality of frequency correlations for said equidistant frequency positions for said first OFDM symbol; (c) repeating steps (a) and (b) for a plurality of subsequent OFDM symbols; and (d) linearly combining said plurality of frequency correlations for said plurality of OFDM symbols obtained in steps (a) through (c), for obtaining the sample timing offset indication wherein the linear combining uses nonzero weights only, wherein step (d) comprises, for each set of frequency correlations determined for said plurality of OFDM symbols in steps (b) and (c): weighting said plurality of determined frequency correlations with a weighting pattern; and calculating sums of said weighted plurality of determined frequency correlations; and then averaging the calculated sums for said plurality of OFDM symbols to obtain said sample timing offset indication.