Abstract: In a multi-carrier system employing OFDM, for example DMT, an adaptive channel equalizer is normally used, operating in the frequency domain. The sampling clock is controlled so that the time delay between the transmitter and the receiver is effectively eliminated. If the information used to control the sampling clock is received from the equalized data stream, it will introduce an ambiguity between the operation of the channel equalizer and the mechanism used to control the sampling clock. Operation of the equalizer can mask an increasing time difference, between transmitter and receiver, which the sample clock controller should be tracking. The present invention eliminates the ambiguities in the operation of the equalizer and sample clock controller by preventing the equalizer accepting time differences which should be corrected by operation of the sample clock controller.

Abstract: When delivering a broadband service, such as xDSL, without inband POTS, it is necessary to separate the analogue POTS signal and the xDSL signal from each other at both the CO (Central Office) and the CP (Customer's Premises). This can be achieved by using an active POTS splitter. The present invention incorporates test functionality for the line between the CP and the CO, or ONU (Optical Network Unit), in the POTS splitter. This enables two-sided measurements on the line, both during installation and during operation. The measurements are performed at the CO and upon request, or when the test device automatically sends a test message/signal. In this way there is no need for field technicians at the CP side. The POTS splitter can have a unique identity code that is transmitted to the CO each time a test is started, or on receipt of a request from the CO.

Abstract: The invention relates to a vibration unit with a grip or a contact surface, to be mounted detachably on exercise machines or on a body part. The vibration unit comprises a vibration generating element (1, 2) and a mounting device (4). According to some embodiments of the invention, the mounting device is adapted for application around or inside a handle of an exercise machine. According to other embodiments of the invention, the mounting device is adapted for application on a frame of an exercise machine or on a body part, by means of various devices. According to other embodiments of the invention, the vibration unit is provided as a separate unit for mounting to a rigid support.

Abstract: The present invention relates to methods, computer program products, a transmitter, a receiver and a transceiver including the transmitter and the receiver in a digital communication system for reducing the transmit power level when there is no user data is to send, i.e. when dummy data is sent instead. That is achieved by defining a symbol alphabet Q and scrambling a bit stream comprising user data and dummy data with randomly generated symbols from the symbol alphabet Q.

Abstract: Zipper is the time-synchronized frequency-division duplex implementation of discrete multi-tome (DMT) modulation. Two communicating Zipper modems transmit DMT symbols simultaneously with a common clock. When all transmitters are time synchronized, the near end cross-talk (NEXT) and near end echoes injected into the received signal are orthogonal to the desired signal. The present invention provides a telecommunications transmission system using zipper and having at least two VDSL systems. Each VDSL system comprises a pair of zipper modems communicating over a cable transmission path. The telecommunications transmission system handles zipper transmission transmitted over the common cable; at least partly mitigates NEXT; and permits transmissions in a first VDSL system which are asynchronous with transmissions in a second VDSL system.

Abstract: In a multi-carrier system employing OFDM, for example DMT, an adaptive channel equalizer is normally used, operating in the frequency domain. The sampling clock is controlled so that the time delay between the transmitter and the receiver is effectively eliminated. If the information used to control the sampling clock is received from the equalized data stream, it will introduce an ambiguity between the operation of the channel equalizer and the mechanism used to control the sampling clock. Operation of the equalizer can mask an increasing time difference, between transmitter and receiver, which the sample clock controller should be tracking. The present invention eliminates the ambiguities in the operation of the equalizer and sample clock controller by preventing the equalizer accepting time differences which should be corrected by operation of the sample clock controller.

Abstract: In a multi-carrier system employing OFDM, for example DMT, an adaptive channel equalizer is normally used, operating in the frequency domain. The sampling clock is controlled so that the time delay between the transmitter and the receiver is effectively eliminated. If the information used to control the sampling clock is received from the equalized data stream, it will introduce an ambiguity between the operation of the channel equalizer and the mechanism used to control the sampling clock. Operation of the equalizer can mask an increasing time difference, between transmitter and receiver, which the sample clock controller should be tracking. The present invention eliminates the ambiguities in the operation of the equalizer and sample clock controller by preventing the equalizer from accepting time differences which should be corrected by operation of the sample clock controller.

Abstract: One problem, frequently encountered with VDSL transmission systems, is that upstream FEXT produced by system users having short wires can be very strong. Users having shorter wires get high bit rates whereas users having longer wires get low bit rates. In extreme cases it may happen that users with wire lengths greater than 1000 meter cannot transmit data upstream. The present invention provides a VDST transmission system with a plurality of modems. The modems are located at varying distances from a central station. There is a target bit rate for each modem. That modems on shorter wires have control means for reducing their transmit power. This reduces the FEXT produced by these modems enabling modems on longer wires to transmit at higher bit rates.

Abstract: The hybrid circuit can be used to substantially reduce near echo signals. The circuit includes a balanced 2-wire to 4-wire hybrid for interconnecting a two wire receive path and a two wire transmit path to a two wire transmission line. The two wire receive path connects the balanced hybrid to an A/D converter and the two wire transmit path connects a D/A converter to the balanced hybrid. The two wire receive path contains a filter, dimensioned to remove signals transmitted from the D/A converter. The invention is particularly adapted for use with FDD and OFDD.

Abstract: A VDSL-modem which is divided into an analog part which is placed in an optical node and a digital part which is placed in a local station. The analog part of the VDSL-modem includes an A/D-converter and D/A-converter, a filter, an amplifier, a hybrid/balun, an adaptive noise attenuator, an optical interface, and possibly an echo canceller. The digital part of the modem includes an FFT/IFFT-processor, a synchronizer, an equalizer, an interleaving unit, an error correction unit, a protocol manager, and an optical interface. The VDSL-modem simplifies synchronization of the modem and reduces power consumption in the optical node. A multiplexor function in the optical node in addition is simpler because it need not manage a protocol.

Abstract: A multi-carrier transmission system has a plurality of transceivers, each having a receiver and a transmitter. Data is transmitted between the transceivers by modulating the data onto a multiplicity of carrier waves in the form of multi-bit symbols, wherein each carrier wave constitutes a channel, and wherein the number of bits per symbol (the bit loading), varies between channels and, within a channel, with time, so that each channel has associated therewith a bit loading parameter.

Abstract: The present invention relates to a compound of formula (1), (2) or (3) having the following structures: Formula 1, 2, 3 wherein X, Y, and Z are independently C or N; A is a direct bond, CH2 or NH;B is a direct bond or NH; n=0-2; R1 is H, optionally substituted C1-4191 alkyl, C3-7191 cycloalkyl, halogen, cyano, nitro, aryl, or alkylaryl; R2 is H, C1-4191 alkyl, or alkoxy C1-4191 alkyl;or R1 and R2 are taken together to form an unsaturated 6-membered aromatic or heterocyclic ring containing one or two heteroatoms fused to the pyridone; R3 is a direct bond, H, C1-4191 alkyl, substituted C1-4191 alkyl, C3-7191 cycloalkyl, aryl or alkylaryl; R4 is a direct bond or H; R5 is C1-4191 alkyl or aryl; R6 and R7 are independently H or C1-4191 alkyl; R8 and R9 are independently H, C1-4191 alkyl, or tert-butoxycarbonyl or R8 and R9 are taken together with the nitrogen to which they are attached and form optionally, unsubstituted, substituted, fused or unsaturated 5-,6-,7-membered heterocycles containing one or two h

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. In a multi-carrier system of the OFDM type, an adaptive channel equalizer, operating in the frequency domain, is often used.

Abstract: A traction vehicle for moving a nose wheel of an aircraft comprises a wheel-mounted chassis including an engagement and hoisting device that can be raised and lowered. The engagement and hoisting device has a nose-wheel holder and a U-shaped stand having an opening facing the aircraft. The nose-wheel holder and the stand are shaped as two separate units and have co-operating journaling members arranged in a circular arc to provide rotational movement between the holder and the stand.

Abstract: A RFI canceller, for use in a subscriber line system using multi-carrier modulation, measures a RFI disturbance in carriers falling within a band of frequencies causing the RFI. The RFI ingress into carriers outside the band of frequencies is estimated, and an error correcting signal derived from the estimation of the RFI ingress is subtracted from a received signal. The subscriber line system may be a VDSL system and the multi-carrier modulation may be DMT. The RFI canceller includes a demodulator for demodulating an incoming data stream to provide a first parallel data stream. A parallel to serial convertor converts the first parallel data stream to a first serial data stream. A digital to analogue convertor converts the first serial data stream to a first analogue signal. An analogue RFI canceller circuit combines the analogue signal with an analogue error correcting signal, to produce a second analogue signal.

Abstract: An arrangement for synchronization of nodes in VDSL-systems, or more exactly, synchronization of optical VDSL-nodes which share a common part of a cable in the access network between subscribers and a local station. A time synchronization is provided towards an external system, for instance GPS, which gives a time reference by which the different nodes can be synchronized. The synchronization reduces the near end cross-talk between the VDSL-systems in the different nodes. Preferably, each respective node includes a receiver for a synchronization signal and an internal oscillator with high stability to deliver a stable clock signal.

Abstract: A method and a system are disclosed for achieving calibration with a minimum of hardware implementations. The method and system apply to base stations that have a “full adaptive antenna” implementation. The calibration accounts for irregularities from the source generator through channelizers, up-converters, mixers, power-amplifiers, and filters. A proposed illustrative embodiment of the set-up and routine accomplishes both transmit path and receive path calibration. An arrangement according to the invention uses the internal base station radio parts by sequentially switching signal paths from transmitter to receiver and thereby not needing external equipment. The necessary hardware switching then is combined with the duplex filters preferably positioned close to the base station.

Abstract: A mechanism for achieving frame synchronization in the frequency domain. In order to synchronize a receiver with a transmitter, on signal acquisition, the interval in which orthogonality exists is determined. Once this has been achieved, an argument function is calculated from the received frame. This argument function can then be used to improve the synchronization. This system is particularly suitable for use in ADSL and VDSL modems which can be used to give broad band access over copper networks. It is also relevant to broad band transmission in mobile and semi-mobile systems for transmission over radio channels.

Abstract: A traction vehicle (2) for moving an aircraft (1) comprises a wheel-mounted chassis (7) and an engagement and hoisting device (12) that can be raised and lowered and comprises a U-shaped stand (17); journalling members (15), flexibly connecting the stand to the chassis; actuators (13), arranged between the stand and the chassis to raise and lower the engagement and hoisting device relative to the chassis; and a nose-wheel holder (18), mounted on the stand to carry and hold the nose wheel (4) of the aircraft. In accordance with the invention, the nose-wheel holder and stand are designed as two units and have co-operating journalling members (70, 71), arranged in a circular arc and defining a vertical axis of rotation for said units, the nose-wheel holder being U-shaped to form a space for receiving the nose wheel. The invention also relates to such an engagement and hoisting device.

Abstract: A circuit, for digitizing an analogue signal includes an analogue to digital converter, a clip processor adapted to estimate a value for clipped digital signal samples, and a buffer adapted to dynamically store a plurality of digitized samples produced by the analogue to digital converter. The clip processor is adapted to read digitized samples from the buffer and replace clipped digitized samples with the estimated values, thereby mitigating the effects of clipping in an output of the circuit.