PROCESS FOR SYNCHRONIZATION OF COMMUNICATION INVOLVING MULTIPLE USER EQUIPMENTS WITH A HEAD-END EQUIPMENT BY MEANS OF OFDM MODULATION IN THE UPSTREAM

摘要

The present invention relates to a method of synchronization on the uplink channel in point-to-multipoint communication by OFDM modulation. The method of the present invention, first, by using the synchronization sequences (3) and performs frequency and time synchronization with respect to (in the user equipment (2) from the head-end equipment (1)) downstream channels; Then, on the basis of the estimate, it is made to correct the sampling frequency of the user equipment, the frequency synchronization of the uplink channel, without correction of the head end equipment is performed. The user equipment is the head-end equipment determines the moment (9) for transmitting the OFDM symbols (7) in the head end equipment to receive the OFDM symbols (7) at a predetermined moment. The access to the uplink channel, by polling the user equipment. The present invention can be used for bidirectional communication for transmitting data through a telecommunication network.