Transceiver Predistortion Feedback for DPA Linearization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional techniques for linearizing digitally controlled power amplifiers (DPAs) in communication transceivers require external equipment and additional hardware, leading to distortion in transmission signals and failure to meet stringent spectral requirements due to nonlinear characteristics.
Innovation Solution
The implementation of predistortion methods and apparatus within the communication transceiver, using a predistorter to linearize the DPA by predistorting input signals and employing a predistortion evaluator to determine and update predistortion values without external hardware, enabling self-calibration and self-compensation procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional linearization techniques are used, then DPA nonlinear characteristics can be countered, but external equipment and additional hardware are required
Solution Approach 1:
The patent combines the linearization function with existing transceiver components. The predistorter is integrated into the transmitter signal path, and the same antenna and receiver components are used for both normal operation and linearization measurement, eliminating the need for separate external equipment
Solution Approach 2:
The transceiver performs self-linearization by using its own receiver to measure the transmitted signal and feed back distortion information to the predistorter. The system calibrates itself without external intervention, with the receiver serving dual purposes for both communication and linearization measurement
2Measurement precision
If conventional linearization techniques are used, then DPA distortion can be measured, but additional hardware components are required
Solution Approach 1:
The receiver is designed to perform multiple functions: normal signal reception and linearization measurement. The same LNA, mixer, and ADC components are used for both communication receiver operations and for measuring the DPA's distortion characteristics during calibration
Solution Approach 2:
The patent uses an internal coupling mechanism where the transmitted signal is coupled back to the receiver through the antenna and front-end components. This internal feedback path serves as an intermediary that enables distortion measurement without requiring external measurement equipment
3Measurement precision
If signal emission is used for DPA linearization, then nonlinear characteristics can be characterized, but signal emission during calibration is required
Solution Approach 1:
The patent segments the PA into multiple stages and selectively activates only the necessary stages during calibration. By enabling intermediate stages while keeping the final high-power stage disabled, the system achieves sufficient signal levels for accurate distortion measurement without emitting full-power signals that would cause interference or violate spectral requirements
Data Source
AI summary
Predistortion methods and apparatus for transmitter linearization in a communication transceiver are disclosed. An example apparatus to linearize a digitally controlled pre-power amplifier included in a transmitter of a communication transceiver disclosed herein comprises a predistorter to predistort an input signal to be processed by the digitally controlled pre-power amplifier, a coupling path within the communication transceiver to couple an output of the digitally controlled pre-power amplifier to an input of a receiver included in the communication transceiver without enabling an output power amplifier stage of a multi-stage power amplifier coupled to an output of the digitally controlled pre-power amplifier, wherein no additional hardware components are required to implement the coupling path within the communication transceiver, and a predistortion evaluator comprising a predistortion calibrator and a predistortion compensator to process data demodulated by the receiver to generate and update predistortion values for use by the predistorter.