Patent ID: 8179996
Filing Date: 2012-05-15
Classification: H04L

Abstract:
1. A method for determining a frame header formed of samples having been coded so that a sample exhibits either value A.e jθ or value A.e j(θ+π) and including at least N1 first samples corresponding to a first determined sequence and N2 second samples corresponding to a second sequence belonging to a set of N second determined sequences, the N2 second samples comprising either pairs of equal values or pairs of opposite values, comprising: a) a correlation step involving N1 samples, in which a correlation is performed between a product of a sample and of a conjugate of an adjacent sample and the corresponding values of the first sequence to generate a first result; b) a correlation step involving N2 samples, in which is performed a sum of the products of a sample of a pair of two successive samples by the conjugate of the other sample in the pair to generate a second result; c) a step of detection of a frame header based on the first and second results; and d) a step of validation of the detected frame header, wherein the step of validation comprises the step of: d1) correcting the first and second samples of the detected header for a determined frequency shift; d2) determining a correlation maximum bearing on the first and second corrected samples, during which step are performed, on the one hand, the correlation between each first corrected sample and the corresponding value of the first sequence and, on the other hand, the correlation between each second sample and the value that it would have in each of the second N determined sequences; d3) resuming, for a determined number of frequency shift values, the steps of correction d1) and of correlation d2) with another frequency shift value; and d4) validating the frame header based on the maximum correlation values determined at step d2).