Patent ID: 6459744
Filing Date: 2002-10-01
Classification: H04L

Abstract:
Method for time synchronization of a receiver of a multicarrier signal consisting of a sequence of symbols each formed by a plurality of carrier frequencies each modulated by a modulation coefficient, and transmitted in a transmission channel;certain of said carrier frequencies, with a position in time and in frequency that is known to said receiver, being reference carrier frequencies bearing a reference coefficient with a value known to said receiver, wherein said method comprises a fine synchronization phase comprising: estimating a pulse response &hcirc;n of said transmission channel of said signal on the basis of reference coefficients belonging to at least two received symbols, so as to provide a fictitious synchronization symbol (non-transmitted), comprising the following steps: extracting the reference coefficients belonging to M symbols comprising successive reference carriers, said reference carriers being separated by L useful carriers in one and the same symbol and being offset by R carriers between two symbols comprising successive reference carriers, with M and L greater than or equal to 2 and R=(L+1)/M; grouping together said extracted reference coefficients so as to form a fictitious synchronization symbol, sub-sampled by a factor R; and calculating a reverse Fourier transform of said fictitious synchronization symbol so as to obtain an estimation of the pulse response &hcirc;n extending over a duration ts/R, ts being a useful period of a symbol; and determining a beginning of a useful part of each of said symbols and/or a feedback control of a clock of the receiver, based on an analysis of said fictitious synchronization symbol.