REDUCTION OF INTERFERENCE IN DISCRETE MULTI-TONE (DMT) BASEDCOMMUNICATIONS SYSTEMS

摘要

An Asymmetric Digital Subscriber Loop (ADSL) Discrete Multi-Tone system h as disjoint and adjacent upstream and downstream channels. During the training phase of an ADSL connection, an ADSL DMT transmitter first determines a round trip propagation delay by transmitting a ranging signal to a far-end ADSL endpoint. During th e subsequent communications phase, the ADSL transmitter synchronizes transmission of DMT symbols to a reference clock. In addition, the cyclic extensions of each DMT symbol are increased as a function of the propagation delay.