Apple Inc.

Intel Corporation

Intel Mobile Communications Gmbh

Infineon Technologies Ag

Christoph Hepp

Andreas Langer

Gunther Kraut

Andreas Menkhoff

Stephan Henzler

Jochen Schrattenecker

Alexander Klinkan

Armando Cova

Christoph Angerer

Nicholas Preyss

Wireless circuitry can include a processor that generates a baseband signal, an upconversion circuit that upconverts the baseband signals to a radio-frequency signal, and an amplifier that amplifies the radio-frequency signal. A tunable delay circuit can be used to selectively delay generation of the radio-frequency signal or to delay generation of another signal intended for the radio-frequency amplifier. The tunable delay circuit can be controlled using a closed-loop delay adaptation scheme. A feedback receiver that is coupled to an output of the amplifier can be used to generate a demodulated signal. A delay error measurement circuit can be used to receive the demodulated signal, to detect a peak by monitoring when an envelope of the demodulated signal crosses a threshold level, to compute an amount of asymmetry in the detected peak, and to output a signal that is used to control the tunable delay circuit.

Wireless circuitry with delay measurement and tuning

Systems, circuitries, and methods for predistorting a digital signal in a transmit chain based on a predistortion function are provided. A method includes shifting a center frequency of an input signal by an offset to generate an adapted signal; predistorting the adapted signal based on a predistortion function to generate a predistorted adapted signal; reverting the shifting of the center frequency of the predistorted adapted signal by the offset to generate a predistorted signal; and causing transmission of the predistorted signal by a transmit chain.

Digital predistortion of signals

A circuit for generating a radio frequency signal is provided. The circuit includes an amplifier configured to generate a radio frequency signal based on a baseband signal. Further, the circuit includes a power supply configured to generate a variable supply voltage based on a control signal indicating a desired supply voltage, and to supply the variable supply voltage to the amplifier. The circuit further includes an envelope tracking circuit configured to generate the control signal based on a bandwidth of the baseband signal, and to supply the control signal to the power supply.

Circuit and a method for generating a radio frequency signal

An apparatus for a mobile communication device adapted for digital pre-distortion that includes a memory and a processor operatively coupled to the memory of the processor. The processor receives a first input signal and also receives a first output signal from a power amplifier that is based on the first input signal. The processor additionally varies compression applied to a second input signal based on the first output signal of the power amplifier, generates a distortion compensation vector for the second input signal based on the first output signal of the power amplifier, and also varies an input excitation signal supplied to the power amplifier based on the first output signal of the power amplifier.

Feedback control systems for wireless devices

Systems, circuitries, and methods for predistorting a digital signal in a transmit chain based on a predistortion function are provided in which the function is determined based on a first digital signal or a first transmit chain state. A method includes: receiving a second digital signal that is input to the transmit chain, wherein the transmit chain is characterized by a present transmit chain state; performing a first operation on the second digital signal to generate an adapted digital signal, wherein the first operation is based on either a relationship between the first digital signal and the second digital signal, or a relationship between the first transmit chain state and the present transmit chain state; predistorting the adapted digital signal based on the predistortion function; and performing a second operation on the predistorted adapted signal, wherein the second operation corresponds to an inverse of the first operation.

An apparatus compensates nonlinearities in envelope tracking (ET) used in a mobile device by limiting a bandwidth of an envelope signal representing an envelope of an input baseband signal to be less than a bandwidth of tracker circuitry, generating a scaled replica of an output signal of the tracker circuitry based on the bandwidth-limited envelope signal, and generating a model distortion signal based on the scaled replica and the input baseband signal, where the model distortion signal emulates ET linearity degradation. The apparatus is further configured to generate an output baseband signal based on the scaled replica, the model distortion signal, and the input baseband signal, where the output baseband signal is pre-distorted relative to the input baseband signal according to the scaled replica, the model distortion signal, and the input baseband signal to compensate for degradations in transmit signal quality due to ET nonlinearities.

Memory predistortion in bandwidth limited envelope tracking

The disclosure relates to a method for improving the power consumption of a transmission chain by varying the operating point of a power amplifier to optimize (e.g., reduce) the current that is consumed by the amplifier. The operating point is varied by changing the bias voltage(s) (e.g., supply voltage, quiescent voltage) of the amplifier to a predetermined value that is chosen based upon the effect that a given transmitted signal modulation scheme characteristic (e.g., channel bandwidth and/or number of subcarriers) has on the operating point of a power amplifier.

PA bias optimization for modulation schemes with variable bandwidth

One embodiment of the present invention relates to a method for improving the power consumption of a transmission chain by varying the operating point of a power amplifier to optimize (e.g., reduce) the current that is consumed by the amplifier. The operating point is varied by changing the bias voltage(s) (e.g., supply voltage, quiescent voltage) of the amplifier to a predetermined value that is chosen based upon the effect that a given transmitted signal modulation scheme characteristic (e.g., channel bandwidth and/or number of subcarriers) has on the operating point of a power amplifier. For example, if the characteristics indicate a good power amplifier performance the linear output power capability of a power amplifier can be lowered, by changing the bias voltage(s) supplied to the power amplifier, to reduce the output power capability and current consumption of the power amplifier.

An amplifier circuit includes a power amplifier configured to amplify an RF input signal to obtain an RF output signal, and a bias controller configured to control a bias of the power amplifier. The bias controller is configured to determine a measure of a load impedance of a load coupled to an output of the power amplifier and provide a bias control signal to adjust the bias of the power amplifier based on the determination of the measure of the load impedance.

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Munich, Germany

Christoph Hepp