SYNCHRONISATION METHOD FOR THE UPLINK CHANNEL IN A POINT-TO-MULTIPOINT COMMUNICATION WITH OFDM MODULATION

摘要

The invention relates to a synchronisation method for the uplink channel in a point-to-multipoint communication with OFDM modulation. The inventive method consists in: first, performing a frequency and time synchronisation in relation to the downlink channel (from the headend equipment (1) to the user equipment (2)) using synchronisation sequences (3); subsequently, on the bas is of the estimation made, correcting the sampling frequency of the user equipment, the frequency synchronisation of the uplink being performed witho ut the headend equipment making corrections. The user equipment determine the moment (9) for sending the OFDM symbols (7) to the headend equipment such th at the headend equipment receives said symbols at predetermined instants. The uplink channel is accessed by interrogating the user equipment. The inventio n can be used in bi-directional communication for sending data via the electrical network.