Method for correcting the frequency of a local carrier in a receiver of a data transmission system and receiver using this method

摘要

A frequency correction method used in the receiver of a data transmission system in which a synchronizing word is transmitted before the data. During each of several steps there are calculated at least one pair of in-phase partial correlations Cr(k-1), Cr(k) and at least one pair of quadrature partial correlations Ci(k-1), Ci(k). The partial correlations of the order (k-1) and (k) in each step relate to two consecutive portions of the same length of a local synchronizing word and the samples of the received demodulated signal; the portions of a step p are greater than the portions of step p-1; the partial correction of a step p are phase-corrected by taking account of the frequency correlation calculated in step p-1. A frequency deviation is calculated from the partial correlations of each step. The final frequency correction to be retained is the sum of the frequency deviations calculated at the end of each step.