公开(公告)号：EP1265394A1

公开(公告)日：2002-12-11

申请号：EP02354091.7

申请日：2002-06-05

申请人： STMicroelectronics S.A.

发明人： Mestdagh, Denis J.

IPC分类号： H04L5/02

CPC分类号： H04L5/143 ,  H04L5/023

摘要： L'invention concerne un procédé de transmission de données entre deux noeuds d'un réseau en multiplexage par division de fréquences orthogonales, consistant : à allouer à chaque noeud au moins un jeu de fréquences d'émission et un jeu de fréquences de réception, le jeu d'émission de chaque noeud étant différent de son propre jeu de réception ; et à utiliser chaque noeud comme relais de réémission d'une transmission qui ne lui est pas destinée.

摘要翻译： 电力线OFDM（正交频分复用）数据传输系统根据调制解调器等级向每个节点（N1-7）分配发射（FBx）和接收（FBy）频率集合，并且使用每个节点作为未发送到 它。 在每个消息中插入循环前缀和后缀以产生预定数量的采样。

公开(公告)号：EP0906681A4

公开(公告)日：2002-10-16

申请号：EP97928752

申请日：1997-05-30

申请人： DIGITAL COMPRESSION TECHNOLOGY

发明人： GRUENBERG ELLIOT L ,  MARSTEN RICHARD B ,  QIAN XIAOMEI ,  VAMAN DHADESUGOOR R

IPC分类号： H03H17/02 ,  H03H11/04 ,  H03M7/30 ,  H04B1/66 ,  H04B14/04 ,  H04L5/14 ,  H04L27/00 ,  H04L27/28 ,  H04L9/18 ,  H04L27/36 ,  H04L27/38

CPC分类号： H04L5/143 ,  H04L27/00

摘要： An improved coding system (fig. 1) for digital compression applicable as a digital compression algorithm for increasing the bandwidth of telecommunications and broadcasting network. The system operates in the transmission regime, not in a baseband (source) so that a transmission channel having a capacity of Mbits/s can deliver Nbit/s channel, where N bits in parallel are combined to the delivered in the 1 Mbit/s channel. The system includes the steps of simultaneously encoding (2) a first group of parallel binary bits (1a-1d) into a digitized voltage amplitude signal in a predetermined bit interval, modulating a carrier with the digitized voltage amplitude signal, transmitting the modulated carrier (fig. 2) over a bandwidth limited communication highway having intrinsic noise therein, demodulating said modulated carrier signal and receiving said digitized voltage amplitude signal, said demodulating means (fig. 3) substantially cancelling said intrinsic noise and improving said output signal noise ratio; and decoding (5 fig. 1) the digitized voltage amplitude signal received in the predetermined bit interval into a second group of parallel binary bits which correspond to the first group of parallel binary bits.

公开(公告)号：EP0883944B1

公开(公告)日：2002-10-16

申请号：EP96924225.4

申请日：1996-07-10

申请人： STMicroelectronics N.V.

发明人： ISAKSSON, Mikael

IPC分类号： H04L5/06

CPC分类号： H04L5/023 ,  H04L5/143

摘要： The invention relates to a procedure to suppress near-end crosstalk at bidirectional broadband communication in wire network, where a cable with at least one pair of wires connects the telephone exchange side and the subscriber side. According to the invention orthogonal subcarriers are utilized in the two transmission directions, for instance by use of DMT line coding technology (Discrete Multitone). The transmission can be symmetric or asymmetric with different numbers of carriers in different transmission directions. The invention solves the problem of near-end crosstalk and echo in the system and increases the transmission capacity, especially at symmetric communication.

公开(公告)号：EP1209840A2

公开(公告)日：2002-05-29

申请号：EP01128040.1

申请日：2001-11-26

申请人： Marconi Communications, Inc.

发明人： Zuhdi, Muneer ,  BuAbbud, George H.

IPC分类号： H04L5/14 ,  H04L25/49 ,  H04L27/02

CPC分类号： H04L27/02 ,  H04L5/143 ,  H04L25/4904

摘要： A method of transmitting and rapidly recovering a burst of data without first having to establish a timing or phase lock. The signals are transmitted as modified Manchester coded signals having pulse transitions at a clocking pulse rate which is a multiple of the clocking pulse rate at which the signals are originally generated, and wherein the MOOSE coded signal is modified by ON-OFF keying.

摘要翻译： 发射和快速而不必首先建立一个定时或相位锁定恢复数据突发的方法。 的信号为反式mitted为具有脉冲过渡改性曼彻斯特编码信号以时钟脉冲速率的所有这是在最初被生成的信号的时钟脉冲频率的倍数，并且worin驼鹿编码信号由ON-OFF键控修改。

公开(公告)号：EP1142249A1

公开(公告)日：2001-10-10

申请号：EP99966429.5

申请日：1999-12-17

申请人： Broadcom Corporation

发明人： JONES, David, C.

IPC分类号： H04L27/26 ,  H04L5/02 ,  H04L5/14

CPC分类号： H04L5/0064 ,  H04L5/0007 ,  H04L5/0046 ,  H04L5/006 ,  H04L5/023 ,  H04L5/143 ,  H04L27/2608

摘要： A method for enhancing the bit rate and/or margin at which quadrature amplitude modulation (QAM) communication is performed includes the steps of varying a spectral allocation and constellation size with which communication is performed, so as to define a combination of spectral allocation and constellation size at which the bit rate and/or margin are enhanced. The spectral allocation can be varied by varying a stop frequency thereof, while maintaining a substantially constant start frequency, so as to mitigate undesirable high frequency content of the bandwidth. Alternatively, both start and stop frequencies may be varied.

公开(公告)号：EP0981222A2

公开(公告)日：2000-02-23

申请号：EP99306377.5

申请日：1999-08-12

申请人： International Business Machines Corporation

发明人： Davis, Gordon T., c/o IBM UK Ltd, IP Law

IPC分类号： H04L5/06 ,  H04M11/06

CPC分类号： H04L5/0053 ,  H04L5/0007 ,  H04L5/0037 ,  H04L5/0046 ,  H04L5/143 ,  H04L5/1438 ,  H04M11/062

摘要： Systems, methods and computer program products are provided for simultaneously transmitting data over a plurality of subscriber lines, such as twisted pair telephone wires, extending between a shared device and a respective plurality of remote devices using a symbol-based discrete multi-tone transmission scheme. A destination code within a first group of frequency bands and modulated data within a second group of frequency bands different from the first group of frequency bands, are transmitted from the shared device to the remote devices. The second group of frequency bands is selected for a subscriber line connected to a remote device having the destination code within the first group of frequency bands. A number of bits transmitted within each of the frequency bands in the second group of frequency bands for a remote device is selected during a communication handshake between the remote device and the shared device by probing a subscriber line connected to the remote device to determine data rates that can be supported by the subscriber line at each of a plurality of frequency bands.

摘要翻译： 提供了系统，方法和计算机程序产品，用于通过使用基于符号的离散多音调传输方案在共享设备和相应的多个远程设备之间延伸的多个用户线路（例如双绞线电话线）上同时发送数据 。 在第一组频带内的目的地代码和与第一组频带不同的第二组频带内的调制数据从共享设备发送到远程设备。 为连接到具有第一组频带内的目的地代码的远程设备的用户线选择第二组频带。 在远程设备和共享设备之间的通信握手期间，通过探测连接到远程设备的用户线路来确定数据速率来选择在远程设备的第二组频带内的每个频带内传输的多个比特 其可以由多个频带中的每个频带处的用户线路支持。

公开(公告)号：EP0956667A1

公开(公告)日：1999-11-17

申请号：EP97953557.0

申请日：1997-12-24

申请人： GTE GOVERNMENT SYSTEMS CORPORATION

发明人： FURUKAWA, Neil, E. ,  SALINGER, Sheldon

IPC分类号： H04L27 ,  H04B15 ,  H04J1 ,  H04L1 ,  H04L5

CPC分类号： H04J1/12 ,  H04L1/0001 ,  H04L1/0003 ,  H04L1/0026 ,  H04L1/206 ,  H04L5/143 ,  H04L27/3827

摘要： An improved digital bi-directional communications transceiver in which the upstream (24) and downstream (22) portions of the frequency spectrum are allocated different bandwidths and positioned at different locations on the frequency spectrum in response to transmission line conditions and impairments such as system provisioning, background noise, radio frequency interference (RFI), crosstalk and reflected signals. The movements of the upstream and downstream carrier frequencies are elastic in that they may be adjusted in near rear-time, involving methods for determining a signal quality parameter (SQP) of the received signal. The SQP is used to estimate the bit error rate (BER) of the received signal and also takes into account the total signal-to-interference ratio (SIR), where the interference includes, crosstalk, RFI and residual echo from the neighboring upstream (24) or downstream (22) channel. Because the carrier frequencies of the upstream (24) and downstream (22) channels are being dynamically allocated, it is necessary to implement a robust carrier acquisition, recovery and lock algorithm. The robust carrier algorithms allow carrier recovery of the transmitted upstream and downsteam signals independent of the particular modulation or symbol rates.

公开(公告)号：EP0876720A1

公开(公告)日：1998-11-11

申请号：EP97901674.0

申请日：1997-01-24

申请人： FRANCE TELECOM ,  TELEDIFFUSION DE FRANCE

发明人： PACE, Daniel ,  VEILLARD, Jacques

IPC分类号： H04L5

CPC分类号： H04L5/143

摘要： Terminals using a two-way RF signal with a downlink channel and an uplink channel, which downlink channel includes a pilot frequency (13) corresponding to the carrier frequency modulating the uplink channel. Corresponding user terminals use an oscillator synchronised with said downlink channel pilot frequency to provide intermediate frequency translation of the downlink channel signals, as well as translation of the uplink channel signals around said pilot frequency. A broadcasting station terminal uses a high-stability microwave oscillator to generate said pilot frequency as well as to provide intermediate frequency translation of the uplink channel signals. The terminals are particularly useful for setting up a feedback channel, especially in the frequency band of millimetric or centimetric wavelengths.

公开(公告)号：EP0835563A2

公开(公告)日：1998-04-15

申请号：EP96923599.0

申请日：1996-06-28

申请人： Scientific Atlanta, Inc.

发明人： BORAZJANI, Ramin

IPC分类号： H04H20 ,  H04H40 ,  H04H60 ,  H04L5 ,  H04L7 ,  H04L12 ,  H04M3 ,  H04M7 ,  H04N7 ,  H04M9

CPC分类号： H04H20/80 ,  H04H20/34 ,  H04H20/42 ,  H04H20/79 ,  H04H40/27 ,  H04H60/97 ,  H04L5/023 ,  H04L5/143 ,  H04L7/0062 ,  H04L12/2801 ,  H04M7/006 ,  H04M7/12 ,  H04M9/027 ,  H04N7/10 ,  H04N7/17309

摘要： A communication system for coupling telephony or other digital networks to a broadband network such as a CATV network. The system transmits a multiplex of telephony signals in the forward band of the broadband network, with individual signals directed to an addressed subscriber. Telephony signals returning from subscribers are modulated onto the reverse band of the broadband network in a frequency division multiplex (FDM). The modulated telephony signals are received at a telephony network interface coupled to the broadband network. A selected plurality of modulated telephony signals are frequency shifted to baseband. The baseband-shifted telephony signals are sampled to generate a plurality of time division multiple access telephony signal samples. A plurality of time division multiple access telephony signal samples are channelized into a serial data stream with a channelizer. The serial data stream is processed with a single digital signal processor (DSP) to derive a plurality of demodulated telephony signals. The demodulated telephony signals are coupled to the telephony network.

公开(公告)号：EP0828363A2

公开(公告)日：1998-03-11

申请号：EP97306860.4

申请日：1997-09-04

申请人： TEXAS INSTRUMENTS INCORPORATED

发明人： Polley, Michael O. ,  Timm, William C. ,  Riley, Terence J.

IPC分类号： H04L27/00 ,  H04M11/06

CPC分类号： H04L5/143 ,  H04L5/023 ,  H04L5/1446 ,  H04L25/4921 ,  H04L27/0008 ,  H04L27/2601 ,  H04M11/062

摘要： A modem that operates selectively in the voice-band frequency band and at higher frequency bands is provided. This modem supports multiple line codes, like DMT and CAP.
The modem uses a Digital Signal Processor (DSP), so that different existing ADSL line codes, such as Discrete MultiTone (DMT) and Carrierless AM/PM (CAP), can be implemented on the same hardware platform. The modem negotiates in real-time, for a desired line transmission rate to accommodate line condition and service-cost requirement.
The line code and rate negotiation process may be implemented at the beginning of each communication session through the exchange of tones between the modems. A four-step MDSL modem initialization process is provided for line code and rate compatibility.
A new synchronization startup procedure for CAP based MDSL modems is provided. The handshake protocol and receiver algorithm allow reliable modem synchronization over severely amplitude distorted channels such as standard telephone twisted-pair wire. The algorithm makes use of a short length sequence to train a synchronizing equalizer at the receiver. After training to this sequence, a matched filter or correlator is used to detect the inverted sync sequence. The detection of the inverted sequence signals the start of the normal reference training of the CAP demodulation equalizers.
The MDSL line connection management process provides a simple, efficient, and flexible interface to manage the line connection between MDSL-C (MDSL in Central Office site) and MDSL-R (MDSL in resident site) in the telecommunication Wide Area Networking environment. An internal state machine in an MDSL modem records and monitors the line status and notifies the state change to the other MDSL and also the host processor. The protocol used for exchanging line connection management messages is a simplified Link Control Protocol (LCP) for MDSL.

摘要翻译： 提供了在语音频带和更高频带中有选择地操作的调制解调器。 该调制解调器支持多种线路代码，如DMT和CAP。 调制解调器使用数字信号处理器（DSP），因此可以在同一硬件平台上实现不同的现有ADSL线路码，如离散多音（DMT）和无载AM / PM（CAP）。 调制解调器实时协商，达到所需的线路传输速率，以适应线路状况和服务成本要求。 可以通过调制解调器之间的音调交换在每个通信会话开始时实现线路码和速率协商过程。 提供四步MDSL调制解调器初始化过程，用于线路代码和速率兼容性。 提供了一种基于CAP的MDSL调制解调器的新的同步启动过程。 握手协议和接收器算法允许在严重幅度失真的信道（如标准电话双绞线）上进行可靠的调制解调器同步。 该算法利用短长度序列在接收机上训练同步均衡器。 在训练到该序列之后，使用匹配滤波器或相关器来检测反相同步序列。 反相序列的检测信号是CAP解调均衡器的正常参考训练的开始。 MDSL线路连接管理流程提供了一种简单，高效，灵活的接口，用于管理电信广域网环境中的MDSL-C（中心局的MDSL）与MDSL-R（常驻站点的MDSL）之间的线路连接。 MDSL调制解调器中的内部状态机记录和监视线路状态，并将状态更改通知给其他MDSL以及主机处理器。 用于交换线路连接管理消息的协议是用于MDSL的简化链路控制协议（LCP）。