Abstract: A digital predistortion (DPD) system includes an input configured to receive an input signal. In some examples, a first signal path configured to generate a first signal based on the input signal. In some examples, an error model provider configured to generate an error model signal modeled after a gate bias error voltage associated with the DPD system. In some examples, a first combiner configured to combine the first signal and the error model signal to generate a first intermediate signal, and the DPD system generates an output signal based at least on the first intermediate signal.

Abstract: A digital predistortion (DPD) system includes an input configured to receive an input signal. In some examples, a first signal path configured to generate a first signal based on the input signal. In some examples, an error model provider configured to generate an error model signal modeled after a gate bias error voltage associated with the DPD system. In some examples, a first combiner configured to combine the first signal and the error model signal to generate a first intermediate signal, and the DPD system generates an output signal based at least on the first intermediate signal.

Abstract: A transmitter for a communication system comprises a digital pre-distortion (DPD) circuit and adaptation circuitry. The DPD circuit is configured to generate a digital intermediate signal by compensating an input signal for distortions resulting from an amplifier. The amplifier is configured to output an output signal based on the digital intermediate signal. The DPD circuit includes one or more an infinite impulse response (IIR) filters configured to implement a first transfer function based on a first parameter, and a second transfer function based on the first parameter and a time constant. The DPD circuit is configured to generate an adjustment signal based on the first transfer function and the second transfer function. The adaptation circuitry is configured to update the first parameter based on the adjustment signal, the input signal, and the output signal.

Abstract: A transmitter for a communication system comprises a digital pre-distortion (DPD) circuit configured to generate a digital intermediate signal by compensating an input signal for distortions resulting from an amplifier, and an adaptation circuitry configured to update the first parameter based on the adjustment signal, the input signal, and an output signal output by the amplifier and based on the digital intermediate signal. The DPD circuit includes an infinite impulse response filter configured to implement a transfer function based on a first parameter, and thermal tracking circuitry configured to generate an adjustment signal corresponding to a thermal change of the amplifier.

Abstract: A circuit for signal classification in a digital pre-distortion (DPD) system is provided. The circuit includes a first frequency path with a positive frequency translation to generate a first power level corresponding to a signal output of the first frequency path, a second frequency path with a negative frequency translation to generate a second power level corresponding to a signal output of the second frequency path, and a third frequency path configured to filter the input signal via a high pass filter (HPF) and to generate a third power level corresponding to a signal output of the third frequency path. The circuit further includes a processing unit configured to compute frequency content metrics corresponding to the input signal based on the first power level, the second power level and the third power level for selecting a set of DPD coefficients for the DPD circuit.

Abstract: Apparatus, method therefor, generally related to signal preconditioning. In such an apparatus, a signal classifier block and a delay block are commonly coupled for receiving an input signal. The delay block is for providing a delayed version of the input signal. The signal classifier block is for classifying the input signal and generating a configuration signal having configuration information for digital predistortion (“DPD”) engine parameterization in response to the input signal classification. A DPD engine is for receiving the delayed version of the input signal and the configuration signal and for providing a predistorted output signal.

Abstract: In an example, an apparatus for signal classification in a digital pre-distortion (DPD) system includes a positive frequency path including a first half-band low pass filter (LPF) operable to filter samples of an input digital samples after positive frequency translation; a negative frequency path including a second half-band LPF operable to filter the samples of the input digital samples after negative frequency translation; a power estimation circuit coupled to the positive frequency path and the negative frequency path, the power estimation circuit operable to determine a first average power based on output of the first half-band LPF, a second average power based on output of the second half-band LPF, and a total average power of the input digital samples; and a controller operable to determine a frequency content metric from the first average power and the second average power, and to select a set of filter coefficients for the DPD system based on the frequency content metric and the total average power.

Abstract: A method and apparatus for efficient drive level selection for, e.g., power amplifiers utilized within a wireless communication system, which utilizes digital predistortion (DPD) to adaptively and predictively select drive level. The DPD, e.g., increases the power amplifier's efficiency while maintaining spectral mask compliance within the designated frequency band of transmission. The method first determines a peak amplitude of an undistorted waveform that is to be transmitted and then predicts the maximum power that is to be transmitted by the power amplifier after the undistorted signal has been predistorted. An over-drive metric is then calculated based upon the predicted drive level of the power amplifier, which indicates whether or not the cascade of the predistorter and the power amplifier is predicted to operate linearly. The over-drive metric may then be used to ensure optimal power amplifier performance, thereby eliminating the need to use overly conservative power amplifier drive settings.

Abstract: A method of generating parameters for a predistortion circuit in an integrated circuit using a matrix is disclosed. The method comprises storing a first column of a first matrix; generating the remaining columns of the first matrix based upon the first column of the matrix; generating a plurality of rows of a second matrix by performing a first set of calculations; and generating the remaining rows of the second matrix by selectively shifting the first rows of the second matrix.

Abstract: A method and apparatus for efficient drive level selection for, e.g., power amplifiers utilized within a wireless communication system, which utilizes digital predistortion (DPD) to adaptively and predictively select drive level. The DPD, e.g., increases the power amplifier's efficiency while maintaining spectral mask compliance within the designated frequency band of transmission. The method first determines a peak amplitude of an undistorted waveform that is to be transmitted and then predicts the maximum power that is to be transmitted by the power amplifier after the undistorted signal has been predistorted. An over-drive metric is then calculated based upon the predicted drive level of the power amplifier, which indicates whether or not the cascade of the predistorter and the power amplifier is predicted to operate linearly. The over-drive metric may then be used to ensure optimal power amplifier performance, thereby eliminating the need to use overly conservative power amplifier drive settings.

Abstract: Communication architectures and methods that implement random phase shift keying. A transmitter and a receiver are coupled by way of a communications channel. The transmitter uses a data source and a mapper that produces an amplitude phase keyed (APK) waveform having a plurality of symbol phases. A transmitter multiplier multiplies random phase signals with the APK waveform to produce a random phase keyed output signal. A vector modulator modulates the random phase keyed output signal. A transmitter mixer mixes the random phase keyed output signal with a local oscillator signal from a transmit local oscillator to produce a modulated carrier signal that is transmitted over the communication channel. The receiver has a demodulator including a receiver mixer that receives and mixes the received modulated carrier signal with a local oscillator signal derived from a receive local oscillator to produce an estimate of the random phase keyed signal. The estimated random phase keyed signal is synchronously sampled.