Predistortion Coefficient Saturation Control Across Multiple LUTs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing distortion compensation devices face performance deterioration due to independent saturation processing of distortion compensation coefficients, leading to uneven saturation across look-up tables (LUTs), which affects the overall distortion compensation performance.
Innovation Solution
A distortion compensation device that monitors and controls saturation processing across LUTs based on coefficient saturation information, ensuring that saturation of coefficients in one LUT does not adversely impact others, thereby maintaining uniformity and optimizing distortion compensation performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If independent saturation processing is applied to distortion compensation coefficients in each LUT, then the saturation processing is simple to implement, but the distortion compensation performance deteriorates due to uneven saturation across LUTs
Solution Approach 1:
The patent merges the saturation processing control across multiple LUTs by introducing a central saturation control unit that coordinates the saturation processing for all LUTs. This ensures uniform saturation characteristics across different LUTs, preventing performance deterioration while maintaining implementation simplicity through centralized control.
Solution Approach 2:
The patent implements feedback mechanisms where the saturation control unit monitors the saturation states of multiple LUTs and adjusts the saturation processing accordingly. This feedback loop ensures that saturation is applied uniformly across all LUTs, maintaining optimal distortion compensation performance while preventing uneven saturation effects.
2Speed
If distortion compensation coefficients are updated without saturation control, then the adaptation speed is fast, but the coefficients become unstable and fall outside valid ranges
Solution Approach 1:
The patent applies saturation processing as a preliminary constraint before coefficient updates are finalized. By pre-defining valid coefficient ranges and applying saturation control beforehand, the system ensures coefficients remain stable and within valid ranges while maintaining fast adaptation speed through efficient boundary enforcement.
Solution Approach 2:
The patent dynamically adjusts the saturation processing parameters based on the current coefficient states and update requirements. This allows the system to maintain fast adaptation when coefficients are within valid ranges while applying appropriate saturation constraints when coefficients approach boundaries, thus balancing speed and stability.
3Stability of the object's composition
If saturation processing is applied to all distortion compensation coefficients, then coefficient stability is improved, but the overall distortion compensation performance degrades due to excessive constraints
Solution Approach 1:
The patent applies saturation processing selectively rather than uniformly to all coefficients. The saturation control unit identifies which specific LUTs or coefficients require saturation constraints based on their individual states, applying constraints only where necessary. This localised approach maintains coefficient stability while avoiding excessive constraints that would degrade overall distortion compensation performance.
Data Source
AI summary
A distortion compensation device includes a distortion compensator that predistorts an input signal based on delay signals and distortion compensation coefficients corresponding to the respective delay signals obtained by applying different amounts of delay to the input signal, a calculator that calculates an error signal based on the predistorted input signal and an output signal from an amplifier that amplifies the predistorted input signal, a calculator that calculates prospective distortion compensation coefficients for updating the distortion compensation coefficients, based on the error signal, a saturation processor that performs saturation processing for bringing, when the prospective distortion compensation coefficients do not fall into a preset range, the prospective distortion compensation coefficients into the preset range, and a controller that controls the updating of the distortion compensation coefficients based on pieces of coefficient saturation information indicating whether the saturation processing is performed on the prospective distortion compensation coefficients.