Abstract: An energy-efficient implementation of a WiFi transceiver is proposed in this disclosure. The WiFi transceiver comprises a receive chain comprising a variable receive (Rx) filter circuit and a variable Rx analog-to-digital converter (ADC) circuit. The receive chain is configured to receive a receive signal during a receive mode of operation, having a receive bandwidth associated therewith and receive a transmit signal associated with a transmit chain of the transceiver during a transmit mode of operation, having a transmit bandwidth associated therewith. The WiFi transceiver further comprises a control circuit configured to dynamically adapt a bandwidth of the variable Rx filter and the variable Rx ADC in the receive chain to the receive bandwidth or to the transmit bandwidth, based on the mode of operation.

Abstract: Examples relate to a concept for a Radio-Frequency (RF) frontend, and for a communication device comprising such an RF frontend. A radio-frequency frontend apparatus comprises a receive branch, comprising circuitry configured to obtain a received signal and a digital pre-distortion feedback signal from an external transceiver device. The radio-frequency frontend apparatus comprises power measurement circuitry configured to generate a first signal that represents a power of the received signal based on the received signal, and to generate a second signal that represents a power of an amplified signal based on the digital pre-distortion feedback signal, the amplified signal being a signal that is amplified by a power amplifier of the external transceiver device.

Abstract: An energy-efficient implementation of a WiFi transceiver is proposed in this disclosure. The WiFi transceiver comprises a receive chain comprising a variable receive (Rx) filter circuit and a variable Rx analog-to-digital converter (ADC) circuit. The receive chain is configured to receive a receive signal during a receive mode of operation, having a receive bandwidth associated therewith and receive a transmit signal associated with a transmit chain of the transceiver during a transmit mode of operation, having a transmit bandwidth associated therewith. The WiFi transceiver further comprises a control circuit configured to dynamically adapt a bandwidth of the variable Rx filter and the variable Rx ADC in the receive chain to the receive bandwidth or to the transmit bandwidth, based on the mode of operation.

Abstract: The present disclosure relates to a concept of nonlinear signal processing which may be used for predistortion for RF power amplifiers. The concept includes generating time variant filter coefficients for a linear filter circuit based on a nonlinear mapping of an input signal, and filtering the input signal with the linear filter circuit using the time variant filter coefficients in order to generate a filtered output signal. Thus, it is proposed to implement a non-linear filter by a time-varying linear filter where the time-varying coefficients are derived from the input signal.

Abstract: An energy-efficient implementation of a WiFi transceiver is proposed in this disclosure. The WiFi transceiver comprises a receive chain comprising a variable receive (Rx) filter circuit and a variable Rx analog-to-digital converter (ADC) circuit. The receive chain is configured to receive a receive signal during a receive mode of operation, having a receive bandwidth associated therewith and receive a transmit signal associated with a transmit chain of the transceiver during a transmit mode of operation, having a transmit bandwidth associated therewith. The WiFi transceiver further comprises a control circuit configured to dynamically adapt a bandwidth of the variable Rx filter and the variable Rx ADC in the receive chain to the receive bandwidth or to the transmit bandwidth, based on the mode of operation.

Abstract: An energy-efficient implementation of a WiFi transceiver is proposed in this disclosure. The WiFi transceiver comprises a receive chain comprising a variable receive (Rx) filter circuit and a variable Rx analog-to-digital converter (ADC) circuit. The receive chain is configured to receive a receive signal during a receive mode of operation, having a receive bandwidth associated therewith and receive a transmit signal associated with a transmit chain of the transceiver during a transmit mode of operation, having a transmit bandwidth associated therewith. The WiFi transceiver further comprises a control circuit configured to dynamically adapt a bandwidth of the variable Rx filter and the variable Rx ADC in the receive chain to the receive bandwidth or to the transmit bandwidth, based on the mode of operation.

Abstract: A circuit with a successive approximation analog-to-digital converter utilizes a feedback path and is operated for example in accordance with the successive approximation method. The feedback path is configured to translate a digital signal in accordance with a prescribed function and to furthermore convert the translated digital signal into an analog feedback signal. For example, the prescribed function can be an exponential function. As such, it can be possible to convert an input signal into an output signal by means of a nonlinear characteristic.

Abstract: According to an embodiment, a circuit includes an amplifier and an open-loop control system. The amplifier has an output stage for amplifying a signal, a power supply for driving a supply voltage of the output stage to different voltage levels responsive to being modulated and a pulse width modulator for modulating the power supply responsive to a mask input. The open-loop control system includes a mask generator and a detector. The mask generator is configured to generate the mask input as a function of the envelope of the signal. The detector is configured to detect discontinuities in the mask input and compensate for the discontinuities.

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 an embodiment, a circuit includes an amplifier and an open-loop control system. The amplifier has an output stage for amplifying a signal, a power supply for driving a supply voltage of the output stage to different voltage levels responsive to being modulated and a pulse width modulator for modulating the power supply responsive to a mask input. The open-loop control system includes a mask generator and a detector. The mask generator is configured to generate the mask input as a function of the envelope of the signal. The detector is configured to detect discontinuities in the mask input and compensate for the discontinuities.

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

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: 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: 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