Abstract: The invention relates notably to a method for transmitting frames on a radio communication channel (RCC), the frames comprising a succession of bursts (B1, . . . , Bn) modulated with at least two different modulation schemes (M1, M2, M3) having different modulation efficiencies, each modulation scheme (M1, M2, M3) having a corresponding average transmitted power. The method according to the invention comprises the steps of: mapping information to be transmitted to modulation symbols using one of the modulation schemes (M1, M2, M3); filtering the modulation symbols using a digital transmission filter with a set of coefficients, the set being chosen from at least two sets of coefficients depending on the modulation scheme (M1, M2, M3) used at the mapping step, the product of the average transmitted power and the gain of the digital transmission filter being smaller than a predefined value for all modulation schemes (M1, M2, M3).

Abstract: The invention relates to a method of receiving digital signals sent in the form of packets and modulated, for example phase and/or amplitude modulated, in which method received analog signals are sampled and optimum sampling times are determined individually for each packet. To estimate the optimum sampling time, at least two independent and uncorrelated estimates are effected and said estimates are combined so that the variance of the estimate obtained with the combination is lower than the lowest of the variances of the independent estimates. Accordingly, the quality of the combination is greater than the quality of the best of the estimates.

Abstract: The invention relates to a method of estimating the frequency offset of a packet of phase modulated symbols received with phase error, the method comprising: applying a phase correction to the symbols of the received packet for all possible pairs of frequency offset and phase offset; and selecting from said offset pairs, the pair which provides the most likely packet of corrected symbols, thereby determining the frequency offset of the received packet. Compared with known solutions, the invention makes it possible to reduce errors concerning estimated frequency. Advantageously, the method comprises a step of quantizing the possible phase corrections, thereby making it possible to reduce the complexity of the calculations to be performed, without degrading performance.

Abstract: The invention relates notably to a method for transmitting frames on a radio communication channel (RCC), the frames comprising a succession of bursts (B1, . . . , Bn) modulated with at least two different modulation schemes (M1, M2, M3) having different modulation efficiencies, each modulation scheme (M1, M2, M3) having a corresponding average transmitted power.