Abstract: One embodiment relates to a method for transitioning from an initial data rate utilizing an initial transmission variable to a new data rate in a multi-carrier communication system. In the method, a first function or a second function is selected to calculate a modified transmission variable, wherein the first function or second function is selected as a function of relative priorities of first and second communication parameters. The new data rate is implemented by modification of transmission variable. Other methods and systems are also disclosed.

Abstract: One embodiment relates to a communication system. The communication system includes a central node that is coupled to a communication channel and configured to individually communicate with a number of network nodes over a frequency range. One of the network nodes can identify a common frequency band that is within the frequency range and on which the central node and network nodes can transmit a signal. Other methods and systems are also disclosed.

Abstract: One embodiment of the present invention relates to a method of limiting data loss in a point-to-multipoint communication system. Data is transferred on a communication channel among network nodes of the point-to-multipoint communication system according to an initial frequency band plan. If a characteristic of the communication channel changes, then data is transferred among the network nodes according to a modified frequency band plan that differs from the initial frequency band plan.

Abstract: A first device receives a first signal transmitted over a transmission line from a second device. The first signal is processed and information is generated that is related to crosstalk from other transmission lines. The information is modulated onto at least one carrier of a plurality of carriers of a second signal to be transmitted from the first device to the second device.

Abstract: The invention relates to a method for reducing the crest factor, comprising the following method steps: (a) IFFT transformation of a data symbol to be transmitted; (b) looking for all peak values within a frame of the IFFT-transformed data symbol the amount of which is above a predetermined threshold; (c) providing a sample correction function; (d) allocating a scaling and phase rotation to the sample correction function according to the amplitude and position of the peak values found; (e) generating a correction signal in the frequency domain from a linear combination of rotated and scaled vectors according to the scaling and position determined; (f) modifying, particularly reducing the peak value of the data symbol to be transmitted by subtracting the correction signal, and IFFT transformation of the peak-value-modified data symbol into the time domain. The invention also relates to a circuit for reducing the crest factor.

Abstract: An arrangement for use in a telecommunication system includes a binder of subscriber lines, a local transceiver circuit, and a far-end crosstalk cancellation circuit. Each of the subscriber lines ends at one of a plurality of remote user terminals. The local transceiver circuit is associated with the binder of subscriber lines and comprises a plurality of substantially identical transceiver modules, each of the transceiver modules being associated to one or a small number of subscriber lines. The far-end crosstalk cancellation circuit is configured to reduce far-end crosstalk between the subscriber lines of the binder, and is operably connected to interface with at least parts of the received data of the respective local transceiver modules. The far-end crosstalk cancellation circuit operable to implement a blind training algorithm for at least one victim subscriber line based on signals received by the respective associated transceiver modules.

Abstract: A method limits the effect of repetitive electrical impulse noise in a communication system. The presence of the repetitive electrical impulse noise is detected during communication service. If the repetitive electrical impulse noise is detected, then a message is transmitted which signals that the repetitive electrical impulse noise is present. Other systems and methods are disclosed.

Abstract: The invention relates to a method for reducing the crest factor of a data symbol to be transmitted in a multi-carrier data transmission system, in which the data symbol to be transmitted is a function of a multiplicity of signals provided within a predetermined data frame and each of these signals is allocated to a carrier, each carrier occupying in each case at least one frequency from a transmit data spectrum, at least one carrier being reserved which is not provided for the data transmission and the predetermined data frame exhibiting the data symbol and a prefix which is derived from a part of the data symbol, in which peak values within the prefix are also taken into consideration for reducing the crest factor.

Abstract: According to the invention, a circuit for reducing the crest factor is provided: (A) with a transmit path with a data symbol to be transmitted; (B) with a model path, which is arranged in parallel with a section of the transmit path, which exhibits a model filter to which the non-oversampled data symbol to be transmitted can be supplied, the non-oversampled data symbol exhibiting a non-flat PSD power spectrum, which exhibits an analysis and evaluation circuit which is arranged following the model filter and which checks whether the time domain function of the data symbol to be transmitted exhibits within a predetermined time interval at least one maximum, the amount of which exceeds a first threshold and/or determines the associated position of the maximum within the time interval, and which, by scaling and displacing a dirac-like sample function generates a correction function in dependence on the position and the amplitude of the maximum; (C) with a subtracting device which is connected to outputs of the mo

Abstract: The inventors have developed a DSL system that can employ digital duplexing for short loops while supporting communications over long loops. For short loops, the system aligns the data symbols at both ends and thereby performs two-way digital duplexing. For longer loops, the system performs semi-digital duplexing: the symbols are aligned for digital duplexing at one end of the loop while echo cancellation is employed at the other end. Over longer loops, the bandwidth for transmissions in one direction may be limited by the complexity of the echo canceller, however, the bandwidth for transmission in the other direction can remain as high as for short loops. Therefore, the system developed by the inventors allows high bandwidth transmission without the loop length limitation associated with conventional VDSL.

Abstract: A communication system is disclosed, and includes a transmission system operable to transmit data to a receiver over a communications medium. The transmission system is configured to provide an indication of a change in system configuration as a synchronization flag temporarily assigned to a plurality of data sub-channels to effectuate an on-line reconfiguration (OLR) of the communication system.

Abstract: In a method for generating a periodic training signal comprising cyclically expanded training symbols for a transceiver which transmits data via a data transmission channel using a predetermined number N of modulated carrier signals an address pointer for addressing a starting address in a memory is calculated for each training symbol on the basis of cyclic expansion parameters and, starting from the calculated starting address, 2*N stored samples of a transformed training symbol are read cyclically from the memory.

Abstract: A method for reducing the crest factor of a multi-carrier signal includes evaluating an inverse Fourier transform of the multi-carrier signal, thereby generating a transformed multi-carrier signal; defining a signal-to-be-corrected to be the transformed multi-carrier signal; generating a simulated output signal; estimating a signal maximum of the simulated output signal; deriving a first correction variable on the basis of the estimate; correcting the signal-to-be-corrected using at least the first correction variable, thereby generating a corrected output signal having a reduced crest factor; defining the corrected output signal to be the signal-to-be-corrected; and iteratively repeating the last five steps until the corrected output signal has a crest factor below a predetermined threshold, or a predetermined number of iterations has occurred.

Abstract: Digital modem for data exchange between a data distribution unit (2) and at least one receiver (3, 4) which can be connected to the digital modem (1) with: a user-data forward signal path (17) for the transmission of user data from the television-data distribution unit (2) to the receiver (3, 4) over broadband user-data forward transmission channels, a backward signal path (42) for the transmission of television-receiver control data from the receiver (3, 4) to the data distribution unit (2) over narrowband backward transmission channels; and with a control-data forward signal path (27) for the transmission of narrowband control data or user data from the data distribution unit (2) to the receiver (3, 4) over narrowband forward transmission channels, it additionally being possible for broadband user data to be transmitted over the control-data forward signal path (27) from the data distribution unit (2) to the receiver (3, 4).

Abstract: A calculation circuit for the division of a fixed-point input signal comprising a sequence of digital data values having a width of n bits by an adjustable division factor 2a for the purpose of generating a divided fixed-point output signal, having a signal input (2) for applying the data value sequence of the fixed-point input signal, a first addition circuit (6), which adds the digital data value present at the signal input (2) to a data value buffer-stored in a register (33) to form a digital first summation data value having a width of max (n, a+1)+1 bits, a shift circuit (11) which shifts the first summation data value present by a data bits toward the right, with the result that the max (n, a+1)?a+1 more significant data bits of the first summation data value are output at an output of the shift circuit (11), a logic circuit (16), which, as a function of the sign of the first summation data value, logically ANDs the a less significant data bits of the first summation data value with a logic combination

Abstract: A method and an apparatus for the transmission of data is provided, wherein the data, in a first operating mode, are transmitted in a plurality of first frequency bands and, in a second operating mode, are transmitted in a plurality of second frequency bands. A number of the first frequency bands is in this case greater than a number of the second frequency bands. The first operating mode is used if there is a large quantity of data to be transmitted. If only a small quantity of data is to be transmitted, switchover to the second operating mode is effected, whereby a power saving can be achieved, particularly in digital parts of a transmitting device and of a receiving device.

Abstract: 1.

Abstract: A method for reducing the crest factor of a multi-carrier signal includes evaluating an inverse Fourier transform of the multi-carrier signal, thereby generating a transformed multi-carrier signal; defining a signal-to-be-corrected to be the transformed multi-carrier signal; generating a simulated output signal; estimating a signal maximum of the simulated output signal; deriving a first correction variable on the basis of the estimate; correcting the signal-to-be-corrected using at least the first correction variable, thereby generating a corrected output signal having a reduced crest factor; defining the corrected output signal to be the signal-to-be-corrected; and iteratively repeating the last five steps until the corrected output signal has a crest factor below a predetermined threshold, or a predetermined number of iterations has occurred.

Abstract: The invention relates to a frequency converter for converting a digital baseband signal (2) having a first frequency (0 Hz) into an analog output signal (8), which is centered around a second frequency (fz, f1+fz, f2+fz), which is switched in rapidly successive frequency jumps, and to a corresponding method. In order to improve the performance of the frequency converter with regard to the rapid switching of the transmission frequency (fz, f1+fz, f2+fz), it is proposed to provide the frequency converter with a digital mixer (9), which transforms the digital baseband signal (2) fed to it to a low intermediate frequency (f1, f2), a D/A converter (3) for converting the baseband signal (4) supplied by the digital mixer (9) into an analog bandpass signal (6), and an analog mixer (7), which transforms the analog bandpass signal (6) with a predetermined constant factor (fz) into a real bandpass signal (8) which is centered around the transmission frequency (fz, f1+fz, f2+fz).

Abstract: 1.