Andrew Corporation

Sumitomo Electric Device Innovations, Inc.

Future Wei Technologies, Inc.

Ruikang Yang

Simon Hamparian

Michael Russo

Zhengxiang Ma

George Philip Vella-Coleiro

Munawar Kermalli

Robert Everest Johnson

Various embodiments of the present disclosure relate to transmitter systems, methods, and instructions for signal predistortion. The transmitter system includes an intermodulation distortion (IMD) filter module configured to filter a detected feedback signal (Y) to generate a targeted filtered signal (Y), a digital pre-distortion (DPD) coefficient estimation module configured to update signal generation coefficients based on comparing an input signal (S) with the targeted filtered signal (Y), and a distortion compensation processing module configured to generate a pre-distorted signal (U) based on the input signal (S) using the updated signal generation coefficients.

Predistortion system with targeted spectrum emission for wireless communication

Various embodiments of the present disclosure relate to transmitter systems, methods, and instructions for signal predistortion. The transmitter system includes a signal decomposition module configured to extract a low-frequency signal (S) and a high-frequency signal (S) from an input signal (S); a distortion compensation processing module configured to generate a pre-distorted low-frequency signal (U) and a pre-distorted high-frequency signal (U) based on the received low-frequency and high-frequency signals using signal generation coefficients; a signal combining module configured to combine the pre-distorted low-frequency signal (U) and the pre-distorted high-frequency signal (U); and a signal characteristic estimation processing module configured to update the signal generation coefficients used by the distortion compensation processing module based on comparing the low-frequency signal (S) and the high-frequency signal (S) with a detected feedback low-frequency signal (Y) and a detected feedback high-frequency signal (Y).

Dualband predistortion system for wireless communication

Apparatus and method embodiments are provided for improving power efficiency in an outphasing amplifier with a non-isolating combiner. The embodiments include reducing the driving power to two power amplifiers (PAs) of the amplifier circuit in the low input signal power region in an asymmetric manner between the two PAs. An embodiment method includes receiving, at a signal decomposer, an input signal, detecting a power amplitude of the input signal, and determining whether the input signal corresponds to one of a plurality of operation modes according to the detected power amplitude of the input signal and a plurality of power thresholds corresponding to the operation modes. Upon determining that the power amplitude of the input signal corresponds to a first mode from the operation modes, the input signal is decomposed into two component signals including at least one signal that has a reduced and scaled amplitude proportional to the input signal.

Apparatus and method for asymmetrically driven partial outphasing power amplifier

Pre-distortion, whose magnitude&#x2014;and preferably phase&#x2014;are frequency-dependent, is applied to an input signal in order to reduce spurious emissions resulting from subsequent amplification of the signal. In preferred embodiments, the pre-distortion technique of the present invention is implemented in combination with the (frequency-independent) magnitude and phase pre-distortion technique described in U.S. patent application Ser. No. 09/395,490 ('the '490 application'), where the frequency-dependent pre-distortion corresponds to amplifier distortion that has a magnitude that is proportional to the frequency offset from the carrier frequency and a phase shift of &#xb1;90&#xb0; on either side of the carrier frequency. The frequency-dependent pre-distortion is generated by differentiating waveforms corresponding to pre-distortion parameters with respect to time and then applying the resulting differentiated pre-distortion parameters to the input signal. Depending on the implementation, the waveforms may be differentiated in either the analog or digital domain.

Digital pre-distortion of input signals for reducing spurious emissions in communication networks

Current and previous input signal power measures are used to generate a combined index value that is applied to one or more composite look-up tables (e.g., an I LUT and a Q LUT) to retrieve one or more pre-distortion parameters (e.g., I and Q). In one embodiment, a combined index value is generated by concatenating current and previous power measures, where each composite LUT maps all possible combinations of the current and previous power measures to the corresponding pre distortion parameters values. By using a composite LUT for each of I and Q, the overall signal processing time of the pre-distortion processing can be greatly reduced relative to the prior art, resulting in a significantly smaller RF delay line used to delay the input signal and thereby providing a less costly and more efficient amplifier system.

Growing community of inventors

Bridgewater, NJ, United States of America

Ruikang Yang