A method, communication system and communication unit for synchronisation for multi-rate communication by transmitting a signal (FIG. 4A) having a synchronisation portion at a first, predetermined chip rate and containing an indication of chip rate used for a further portion; receiving the transmitted signal, recovering the indication from the synchronisation portion at the first, predetermined chip rate, and recovering information in the further portion at the chip rate indicated by the indication. This provides improved efficiency in supporting multi-chip rates.