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    IMPROVEMENTS IN, OR RELATING TO, MULTI-CARRIER TRANSMISSION SYSTEMS
    8.
    发明授权
    IMPROVEMENTS IN, OR RELATING TO, MULTI-CARRIER TRANSMISSION SYSTEMS 失效
    在多载波传输系统中的改进或与之相关的改进

    公开(公告)号：EP0922341B1

    公开(公告)日：2002-11-13

    申请号：EP97937939.3

    申请日：1997-09-01

    Applicant: STMicroelectronics N.V.

    Inventor： ISAKSSON, Mikael ,  JOHANSSON, Magnus ,  TONVALL, Harry ,  OLSSON, Lennart ,  STEFANSSON, Tomas ,  ÖHMAN, Hans ,  BAHLENBERG, Gunnar ,  ISAKSSON, Anders ,  ÖKVIST, Göran ,  LJUNGGREN, Lis-Marie ,  NORDSTRÖM, Tomas ,  ISAKSSON, Lars-Ake ,  BENGTSSON, Daniel ,  HAKANSSON, Siwert ,  WEN, Ye

    IPC: H04L5/06 ,  H04L27/26

    CPC classification number: H04L5/006 ,  H04L5/0007 ,  H04L5/0037 ,  H04L5/0046

    Abstract: The invention relates to a multi-carrier transmission system, particularly a DMT system, in which data is transmitted between two transceivers using a plurality of carriers, the frequency bandwidth of the system being divided between said plurality of carriers, the transmission system being 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 varying in dependence on their respective locations. In accordance with the invention the transmission system includes allocation means for allocating the traffic of subscriber equipments having a shorter length of cable to tones starting from a higher frequency band of said system bandwidth.

    Abstract translation: 本发明涉及一种多载波传输系统，特别是一种DMT系统，其中使用多个载波在两个收发信机之间传输数据，该系统的频带宽度在所述多个载波之间分配，传输系统适用于 在包括具有不同信道特性并且共存于相同电缆上的多个用户设备的异构网络中进行操作，每个用户终端的电缆长度根据它们各自的位置而变化。 根据本发明，传输系统包括分配装置，用于将具有较短电缆长度的用户设备的业务分配到从所述系统带宽的较高频带开始的音调。

    IMPROVEMENTS IN, OR RELATING TO SYNCHRONISATION
    10.
    发明授权
    IMPROVEMENTS IN, OR RELATING TO SYNCHRONISATION 失效
    改进技术或与之相关的SYNC

    公开(公告)号：EP0920765B1

    公开(公告)日：2003-04-02

    申请号：EP98908383.7

    申请日：1998-02-27

    Applicant: STMicroelectronics N.V.

    Inventor： OLSSON, Lennart ,  BAHLENBERG, Gunnar ,  BENGTSSON, Daniel ,  HAKANSSON, Siwert ,  ISAKSSON, Anders ,  ISAKSSON, Lars-Ake ,  ISAKSSON, Mikael ,  JOHANSSON, Magnus ,  LATHI, Mauritz ,  LJUNGGREN, Lis-Marie ,  LUNDBERG, Hans ,  NORDSTRÖM, Tomas ,  OLOFSSON, Sven-Rune ,  STEFANSSON, Tomas ,  ÖHMAN, Hans ,  ÖKVIST, Göran

    IPC: H04L27/26 ,  H04L5/22

    CPC classification number: H04L27/2662 ,  H04L27/2657 ,  H04L27/2672 ,  H04L27/2678

    Abstract: With OFDM systems the frequency domain data is the Fourier transform of the received time domain OFDM frames. The time domain frames must be sampled, at the receiver, in synchronism with the transmitter, so that each received frame contains data from only a single transmitted frame. It is vital for this synchronism to be maintained in order to maintain the orthogonality of the frames. A typical multi-carrier system, of the OFDM type, which uses a cyclic prefix permits orthogonality to be maintained when there is a small deviation from exact frame synchronisation. Because the signalling interval includes both an entire frame and the cyclic prefix, which is a repetition of part of the frame, a frame sampled within the signalling interval will contain data from only one frame. Since the signalling interval is greater than the frame period, this gives some leeway in frame alignment. The present invention provides a mechanism for achieving frame synchronisation, in the frequency domain, by utilising this fact. The first step in synchronising a receiver with a transmitter, on signal acquisition, is to determine the interval in which orthogonality exists. Once this has been achieved an argument function is calculated from the received frame. This argument function can then be used to improve the synchronisation. The present invention is particularly suitable for use in ADSL and VDSL modems which can be used to give broadband access over copper networks. The invention is also of relevance to broadband transmission in mobile and semi-mobile systems for transmission over the radio channels.

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