METHOD FOR TIME SYNCHRONISATION OF COMMUNICATION SYSTEM BASED ON ORTHOGONAL FREQUENCY DIVISION MULTIPLEX CHANNELS ON PREAMBLE

摘要

FIELD: radio engineering.;SUBSTANCE: invention relates to radio engineering, in particular, to a method for time synchronisation of a communication system. Said technical result is achieved also due to that decision function is a square of modulus of integrated cross-correlation function of received signal and reference preamble symbol without cyclic prefix, which is not transmitted through transmission channel, and was previously known. Preamble symbol is a delta-correlated noise-like signal. Use of said property when processing results in higher accuracy due to abrupt narrowing of region of maximum of decision function. Essence of method consists in that to perform time synchronisation, a decision function is used (which substantially represents square of modulus of cross-correlation function) calculated via inverse Fourier transformation of product of received signal spectrum and complex conjugated spectrum of reference preamble symbol. Moduli of calculation of direct and inverse Fourier transforms are necessarily present in all OFDM and DMT modems, which simplifies hardware implementation of present method.;EFFECT: technical result is higher accuracy due to abrupt narrowing of region of maximum of decision function.;1 cl, 12 dwg, 1 tbl