Beamforming Digital Predistortion for Side Lobe Distortion Control
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Solution Overview
Problem
Traditional digital predistortion technologies are not suitable for 5G or Massive MIMO systems due to high resource consumption and inability to suppress non-linear distortion of side lobes, leading to interference and reduced coverage.
Innovation Solution
A digital predistortion method that redistributes predistortion components using weighted coefficients based on the digital baseband signal and synthesized signals in the main lobe direction, minimizing non-linear distortion in side lobes while maintaining signal quality in the main lobe direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional digital predistortion technology is used to linearize every power amplifier, then each power amplifier achieves linearization, but calculating and hardware resource consumption becomes unacceptable, increasing equipment volume and power
Solution Approach 1:
The patent segments the predistortion function by direction: beam-oriented predistortion is applied to main lobe directions while side lobe directions use traditional predistortion. This segmentation allows resource optimization by applying different predistortion strategies to different spatial regions, reducing overall hardware complexity while maintaining necessary linearization performance.
Solution Approach 2:
The patent implements local quality by applying beam-oriented predistortion specifically to main lobe directions where high signal quality is critical, while side lobe directions use conventional approaches. This localized optimization ensures high performance where needed while reducing resource consumption in less critical areas.
2Device complexity
If beam-oriented digital predistortion is used to linearize synthetic signal in main lobe direction, then hardware resource consumption is reduced, but non-linear distortion of side lobe cannot be suppressed, affecting coverage and generating interference
Solution Approach 1:
The patent introduces dynamic switching between beam-oriented predistortion and traditional predistortion based on spatial direction. The system dynamically selects the appropriate predistortion method for each direction, applying beam-oriented predistortion to main lobe directions and traditional predistortion to side lobe directions, thereby suppressing non-linear distortion dynamically across different spatial regions.
Solution Approach 2:
The patent employs feedback mechanisms to monitor and adjust predistortion performance in different directions. By measuring the actual non-linear distortion in side lobe directions and feeding this information back to the predistortion controller, the system can adaptively adjust predistortion parameters to suppress harmful distortions while maintaining resource efficiency.
Data Source
AI summary
The disclosure discloses a digital predistortion (DPD) device and method. The DPD device comprises a predistorter configured to obtain a predistortion component from a digital baseband signal using a predistortion parameter and output the predistortion component; and a weighting unit configured to: obtain one or more weighted predistortion components by applying the predistortion component to one or more weighting coefficients, and obtain one or more predistortion correction signals by combining the digital baseband signal and the one or more weighted predistortion components, wherein the one or more weighting coefficients are determined based on the digital baseband signal, the predistortion component, and a synthesized signal in a main lobe direction obtained by combining radio frequency signals from a beamforming array.