Method of determining, at a receiver of a communication system, the time of start of each of a series of OFDM symbols (210, 220, 230, 240, 250) forming an OFDM packet transmitted over a time-varying channel to the receiver, wherein one or more first OFDM symbols (210, 220) of the OFDM packet comprises a plurality of consecutive copies of a short training sequence (t 1, t 2, t 3, t 4, t 5, t 6, t 7, t 8, t 9, t 10), the short training sequence being made of a plurality of time-domain samples; the method comprising: - determining a coarse time index indicative of the coarse time of start of the first OFDM symbol subsequent to the one or more first OFDM symbols based on at least the short training sequences of the one or more first OFDM symbols - determining a fine time index indicative of the fine time of start of the first OFDM symbol subsequent to the one or more first OFDM symbols wherein the fine time index may be different from the coarse time index; and, - determining the time of start of each of the series of OFDM symbols forming the OFDM packet based on the fine time index; wherein - the coarse time index and the fine time index respectively correspond to the time of start of one of the plurality of the time-domain samples; - a coarse time-domain sample corresponding to the coarse time index is comprised within a coarse estimation error interval ranging from a lower value, corresponding to a number P of time-domain samples situated before the coarse time-domain sample, to an upper value corresponding to a number M of time-domain samples coming after the coarse time-domain sample, wherein P and M values may be different from each other and may be equal to zero; - the time-domain samples comprised in the coarse estimation error interval are converted into associated frequency domain samples; - a modulation-quality metric value is determined for each frequency domain samples; and, - the fine time index is the time index corresponding to one of the coarse estimation error interval samples having its associated frequency domain sample having the lowest modulation-quality metric value. - determining a coarse time index indicative of the coarse time of start of the first OFDM symbol subsequent to the one or more first OFDM symbols based on at least the short training sequences of the one or more first OFDM symbols - determining a fine time index indicative of the fine time of start of the first OFDM symbol subsequent to the one or more first OFDM symbols wherein the fine time index may be different from the coarse time index; and, - determining the time of start of each of the series of OFDM symbols forming the OFDM packet based on the fine time index; wherein - the coarse time index and the fine time index respectively correspond to the time of start of one of the plurality of the time-domain samples; - a coarse time-domain sample corresponding to the coarse time index is comprised within a coarse estimation error interval ranging from a lower value, corresponding to a number P of time-domain samples situated before the coarse time-domain sample, to an upper value corresponding to a number M of time-domain samples coming after the coarse time-domain sample, wherein P and M values may be different from each other and may be equal to zero; - the time-domain samples comprised in the coarse estimation error interval are converted into associated frequency domain samples; - a modulation-quality metric value is determined for each frequency domain samples; and, - the fine time index is the time index corresponding to one of the coarse estimation error interval samples having its associated frequency domain sample having the lowest modulation-quality metric value.