Abstract: An RF transmitter arrangement using analog pre-distortion is disclosed. The arrangement includes lower bandwidth circuitry, an analog pre-distorter, and a non-linear amplifier chain. The lower bandwidth circuitry is configured to generate an analog signal. The analog pre-distorter is configured to apply a non-linear distortion to the analog original signal based on a coupled feedback signal in order to generate an RF output signal. The non-linear amplifier chain is configured to amplify the RF output signal to generate a transmission signal relative to the analog original signal. The coupled feedback signal is derived from the transmission signal.

Abstract: Vector Control Entity and method therein for Disorderly Leaving Events, DLEs, causing Sudden Termination Change in a DSL system. The method comprises, when a DLE occurs on a line m in a vectored group of DSL lines, and the transmission on line m is, at least partly, continued: obtaining at least one error sample from CPEs connected to other lines in the vectored group of DSL lines, and calculating an estimate of the channel coefficients, H?, changed due to the DLE. The estimate is calculated based on the at least one error sample, and thus a channel estimate is provided. The method further comprises modifying a downstream precoder, based on the channel estimate, such that retraining of the other lines in the vectored group due to the DLE is avoided. The estimate of the channel coefficients is calculated based on the model H?=H+C?H.

Abstract: A non-linear pre-distortion engine maintaining constant peak power at its output is disclosed. The engine includes a compression estimator, a crest factor reduction processor, a digital pre-distorter and a power amplifier. The compression estimator is configured to generate a compression estimate based on an input signal and a feedback signal. The feedback signal is based on an RF output signal. The crest factor reduction processor is configured to reduce a crest factor of the input signal to generate a crest factor reduced signal based on the compression estimate. The digital pre-distorter is configured to apply a pre-distortion to the crest factor reduced signal after an initial phase and generate a pre-distorted signal based on pre-distortion parameters. The power amplifier is configured to amplify the pre-distorted signal to generate the RF output signal.

Abstract: There is provided spectrum shaping of a signal. A frequency-domain representation of the signal to be spectrum-shaped is provided. The signal is associated with a set of constellation points having a minimum distance. A spectrum-shaped signal is determined by altering a proper subset of the constellation points while maintaining the minimum distance between all of the constellation points. The spectrum-shaped signal is transformed into a time-domain signal.

Abstract: Vector Control Entity and method therein for Disorderly Leaving Events, DLEs, causing Sudden Termination Change in a DSL system. The method comprises, when a DLE occurs on a line m in a vectored group of DSL lines, and the transmission on line m is, at least partly, continued: obtaining at least one error sample from CPEs connected to other lines in the vectored group of DSL lines, and calculating an estimate of the channel coefficients, H?, changed due to the DLE. The estimate is calculated based on the at least one error sample, and thus a channel estimate is provided. The method further comprises modifying a downstream precoder, based on the channel estimate, such that retraining of the other lines in the vectored group due to the DLE is avoided. The estimate of the channel coefficients is calculated based on the model H?=H+C?H.

Abstract: Transceiver device and method therein, for baseband processing of signals associated with TDD communication over wire lines. The method involves use of a single burst I/O N-point complex FFT kernel for baseband processing of receive and transmit signal blocks, where the processing involves simultaneously performing a respective FFT or IFFT of two N-sample signal blocks.

Abstract: An RF transmitter arrangement using analog pre-distortion is disclosed. The arrangement includes lower bandwidth circuitry, an analog pre-distorter, and a non-linear amplifier chain. The lower bandwidth circuitry is configured to generate an analog signal. The analog pre-distorter is configured to apply a non-linear distortion to the analog original signal based on a coupled feedback signal in order to generate an RF output signal. The non-linear amplifier chain is configured to amplify the RF output signal to generate a transmission signal relative to the analog original signal. The coupled feedback signal is derived from the transmission signal.

Abstract: A non-linear pre-distortion engine maintaining constant peak power at its output is disclosed. The engine includes a compression estimator, a crest factor reduction processor, a digital pre-distorter and a power amplifier. The compression estimator is configured to generate a compression estimate based on an input signal and a feedback signal. The feedback signal is based on an RF output signal. The crest factor reduction processor is configured to reduce a crest factor of the input signal to generate a crest factor reduced signal based on the compression estimate. The digital pre-distorter is configured to apply a pre-distortion to the crest factor reduced signal after an initial phase and generate a pre-distorted signal based on pre-distortion parameters. The power amplifier is configured to amplify the pre-distorted signal to generate the RF output signal.

Abstract: A non-linear pre-distortion engine maintaining constant peak power at its output is disclosed. The engine includes a compression estimator, a crest factor reduction processor, a digital pre-distorter and a power amplifier. The compression estimator is configured to generate a compression estimate based on an input signal and a feedback signal. The feedback signal is based on an RF output signal. The crest factor reduction processor is configured to reduce a crest factor of the input signal to generate a crest factor reduced signal based on the compression estimate. The digital pre-distorter is configured to apply a pre-distortion to the crest factor reduced signal after an initial phase and generate a pre-distorted signal based on pre-distortion parameters. The power amplifier is configured to amplify the pre-distorted signal to generate the RF output signal.

Abstract: The present disclosure relates to a low-complexity transmitter architecture that drives phase modulators with digital signals to generate a pulse width modulated (PWM) signal that is transmitted by an antenna. In some embodiments, the system has a pre-processing element that generates first and second digital control signals from a digital baseband signal. A first phase modulation component introduces a first phase shift into a first local oscillator signal based upon the first control signal and generates a first digital signal corresponding to the first phase shift. A second phase modulation component introduces a second phase shift into the first local oscillator signal based upon the second control signal and generates a second digital signal corresponding to the second phase shift. A combination element is configured to combine the first and second digital output signals to generate an RF pulse width modulated (RF-PWM) signal.

Abstract: A non-linear pre-distortion engine maintaining constant peak power at its output is disclosed. The engine includes a compression estimator, a crest factor reduction processor, a digital pre-distorter and a power amplifier. The compression estimator is configured to generate a compression estimate based on an input signal and a feedback signal. The feedback signal is based on an RF output signal. The crest factor reduction processor is configured to reduce a crest factor of the input signal to generate a crest factor reduced signal based on the compression estimate. The digital pre-distorter is configured to apply a pre-distortion to the crest factor reduced signal after an initial phase and generate a pre-distorted signal based on pre-distortion parameters. The power amplifier is configured to amplify the pre-distorted signal to generate the RF output signal.

Abstract: The present disclosure relates to a low-complexity transmitter architecture that drives phase modulators with digital signals to generate a pulse width modulated (PWM) signal that is transmitted by an antenna. In some embodiments, the system has a pre-processing element that generates first and second digital control signals from a digital baseband signal. A first phase modulation component introduces a first phase shift into a first local oscillator signal based upon the first control signal and generates a first digital signal corresponding to the first phase shift. A second phase modulation component introduces a second phase shift into the first local oscillator signal based upon the second control signal and generates a second digital signal corresponding to the second phase shift. A combination element is configured to combine the first and second digital output signals to generate an RF pulse width modulated (RF-PWM) signal.

Abstract: One embodiment relates to a system which includes a pre-distortion unit, a power amplifier circuit, a power amplifier model, and a parameter estimation unit. The pre-distortion unit is configured to pre-distort an input signal based on a model parameter by directly computing the model inverse in an iterative fashion, thereby providing a pre-distorted signal. The power amplifier circuit is configured to amplify the pre-distorted signal. The power amplifier model is configured to model amplification of the pre-distorted signal by the power amplifier circuit based on the pre-distorted signal and the model parameter. Based on the pre-distorted signal and an error signal, the parameter estimation unit is configured to update the model parameter provided to the pre-distortion unit and the power amplifier model. The error signal represents a difference between an output signal from the power amplifier circuit and a modeled output signal from the power amplifier model.

Abstract: There is provided spectrum shaping of a signal. A frequency-domain representation of the signal to be spectrum-shaped is provided. The signal is associated with a set of constellation points having a minimum distance. A spectrum-shaped signal is determined by altering a proper subset of the constellation points whilst maintaining the minimum distance between all of the constellation points. The spectrum-shaped signal is transformed into a time-domain signal.

Abstract: A nonlinear distorter is configured to mitigate nonlinearity from a nonlinear component of a nonlinear system. The nonlinear distorter operates to model the nonlinearity as a function of a piecewise polynomial approximation applied to segments of a nonlinear function of the nonlinearity. The nonlinear distorter generates a model output that decreases the nonlinearity of the nonlinear component.

Abstract: Transceiver and method therein, for baseband processing of signals associated with TDD communication over wire lines. The method involves use of a single streaming I/O N/2-point complex FFT kernel for baseband processing of N-sample transmit and receive signal blocks. The processing comprises converting the N-sample signal blocks into intermediate N/2-point signals.

Abstract: Transceiver device and method therein, for baseband processing of signals associated with TDD communication over wire lines. The method involves use of a single burst I/O N-point complex FFT kernel for baseband processing of receive and transmit signal blocks, where the processing involves simultaneously performing a respective FFT or IFFT of two N-sample signal blocks.

Abstract: The present invention relates to a precoder for a communication system arranged to provide transmission blocks for transmission over a transmission channel based on inputted symbol blocks. The precoder is arranged to pre-distort each symbol block based on an estimate of the characteristics of the transmission channel so that the corresponding transmission block appears to be undistorted after transmission over the transmission channel. In accordance therewith, the precoder is arranged to apply Tomlinson-Harashima precoding on a sum of a first measure corresponding to predistortion so as to remove intrasymbol interference and a second measure corresponding to predistortion so as to remove intersymbol interference. The present invention further relates to a method for providing transmission blocks for transmission over a transmission channel in a communication system.

Abstract: The present invention relates to a precoder for a communication system arranged to provide transmission blocks for transmission over a transmission channel based on inputted symbol blocks. The precoder is arranged to pre-distort each symbol block based on an estimate of the characteristics of the transmission channel so that the corresponding transmission block appears to be undistorted after transmission over the transmission channel. In accordance therewith, the precoder is arranged to apply Tomlinson-Harashima precoding on a sum of a first measure corresponding to predistortion so as to remove intrasymbol interference and a second measure corresponding to predistortion so as to remove intersymbol interference. The present invention further relates to a method for providing transmission blocks for transmission over a transmission channel in a communication system.

Abstract: The invention creates a method and a device for digitally transmitting analog signals, in which oversampling is performed in analog/digital and digital/analog converters. In this arrangement, a digital/analog conversion is performed which, in particular, is suitable for VDSL systems. A transmitted digital transmission signal (110) is supplied to a mixing unit (201) and in the mixing unit (201), a receive noise signal (211) applied to a receive noise source terminal (209) is superimposed on the digital transmission signal (110). An interpolation filter unit (203), in combination with a subsequent noise shaping device (205), provides an increase in the frequency bandwidth, resulting in suitable oversampling.