Abstract: A multi-carrier transmission system using DMT. It is known to recover a receiver sample and clock from a reserved carrier, a pilot carrier having a fixed phase. A sampling clock oscillator in a receiver is then phase locked to the pilot carrier. Multi-carrier receivers, such as DMT receivers, are normally equipped with an FFT processor. A complex number representing the pilot carrier is then available from the FFT processor output. If an FFT processor is not available, a one frequency DFT processor can be provided to produce a complex estimate of the pilot carrier. In a DMT system, frame synchronization is handled separately from sampling clock synchronization, although the two processes are intimately related and frame synchronization must be acquired before sampling clock synchronization.

Abstract: A multi-carrier transmission system, particularly a discrete multi-tone (DMT) system. Data is transmitted between two transceivers using a plurality of carriers. The frequency bandwidth of the system is divided between the plurality of carriers. The transmission system is adapted for operation in a heterogeneous network including a number of subscriber equipments having different channel characteristics and coexisting on the same cable. The length of cable for each subscriber terminal varies in relation to its respective location. The transmission system includes an allocation device for allocating the traffic of subscriber equipments having a shorter length of cable to tones starting from a higher frequency band of the system bandwidth.