Preamble design for symbol synchronisation in frequency-selective fading channels

In this study, a two-step method for designing multi-tone preambles is proposed and its performance in the frequency-selective fading channel is optimised. The first step is to find an analytical solution for obtaining the optimum normalised tone frequencies of the multi-tone preamble in order to perform better in frequency-selective fading channel. To measure the quality of the preamble, the authors also propose a timing metric that provides a measure of impulsiveness of the auto-correlation function of the preamble. The second step is to de-normalise the tone frequencies to obtain the best performance in the presence of additive white Gaussian noise regarding a specific number of tones in a specific frequency interval. The tone frequencies are de-normalised using a factor that maximises the impulsiveness of the auto-correlation of the preamble. To compare the authors´ work with other methods, computer simulations are done using Monte Carlo method and the mean square error of the timing estimation is then calculated. Their work is mostly suitable for use in applications with high signal-to-noise ratio (SNR) such as M-quadrature amplitude modulation high rate links because they show that their method outperforms other methods in high SNR scenarios.